Research IndicatorsGraph generated 13 March 2017 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 13 March, 2017 using data from PubMed, MeSH and CancerIndex
Specific Cancers (4)
Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.
Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
Cancer Genome Anatomy Project, NCI
COSMIC, Sanger Institute
Somatic mutation information and related details
TICdb, Universidad de Navarra
Search the database of Translocation breakpoints In Cancer for "TFE3"
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: TFE3 (cancer-related)
BACKGROUND: Xp11.2 translocation/transcription factor E3 (TFE3) rearrangement renal cell carcinoma (RCC) is a rare subtype of RCC with limited clinical and pathological data.
CASE PRESENTATION: Here we present an unusual high-grade Xp11.2 translocation RCC with a rhabdoid feature and SMARCB1 (INI1) inactivation in a 40-year-old man with end-stage kidney disease. The histological examination of the dissected left renal tumor showed an organoid architecture of the eosinophilic or clear neoplastic cells with necrosis and high mitotic activity. In some areas, non-adhesive tumor cells with eccentric nuclei were observed. Immunohistochemically (IHC), the tumor cells are positive for TFE3 and the renal tubular markers (PAX2 and PAX8), and completely negative for SMARCB1, an oncosuppressor protein. Break-apart florescence in situ hybridization and reverse transcription polymerase chain reaction confirmed TFE3 rearrangement on Xp11.2 and the presence of ASPSCR1-TFE3 fusion gene. DNA sequencing revealed a frameshift mutation in exon 4 of SMARCB1 gene.
CONCLUSION: It is important to recognize this rare RCC with both TFE3 rearrangement and SMARCB1 inactivation, as the prognosis and therapeutic strategies, particularly targeted therapies for such tumors, might be different.
BACKGROUND: Renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) is a rare subtype of RCC which is firstly described as a distinct entity in 2004 so that clinical characteristics of Xp11.2 RCC in different gender and age are unknown. The purpose of systematic review and meta-analysis is to provide a comprehensive assessment on them.
METHODS: MEDLINE, EMBASE and Cochrane databases were searched for studies which evaluate the clinical characteristics of Xp11.2 RCC. The literature published between July 2004 and May 2014 was searched.
RESULTS: A total of 15 studies with 147 participants were included. The meta-analysis demonstrated that number of patients of all age in female was higher than in male with pooled OR of 3.93(95 % CI = 1.66-9.34). However, incidence of distant metastases (OR = 0.34, 95 % CI = 0.12-1.57) and lymphatic metastases (OR = 0.51, 95 % CI = 0.14-1.91), tumor stage (OR = 0.85, 95 % CI = 0.34-2.15) and overall survival (OS) (OR = 0.46, 95 % CI = 0.05-4.34) between male and female were comparable. Incidence in female was higher than in male with pooled OR of 5.13(95 % CI = 1.67-15.72) in adults, while in children no gender-related predominance (OR = 1.19, 95 % CI = 0.38-3.72) was observed. In addition, incidence of distant metastases (OR = 1.00, 95 % CI = 0.13-7.84) and lymphatic metastases (OR = 1.00, 95 % CI = 0.07-13.67) and tumor stage (OR = 1.94, 95 % CI = 0.20-19.03) between children and adults were comparable. Survival curves presented comparable outcomes between male and female (P = 0.707) as well as between children and adults (P = 0.383).
CONCLUSIONS: Female patients with Xp11.2 RCC in adults exhibit a high incidence compared to male, but not in children. Comparable clinical characteristics including incidence of distant and lymphatic metastases, tumor stage and prognosis is presented between male and female as well as between children and adults.
Chen X, Zhu Q, Li B, et al.Renal cell carcinoma associated with Xp11.2 translocation/TFE gene fusion: imaging findings in 21 patients.
Eur Radiol. 2017; 27(2):543-552 [PubMed
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OBJECTIVES: To characterize imaging features of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE gene fusion.
METHODS: Twenty-one patients with Xp11.2/TFE RCC were retrospectively evaluated. Tumour location, size, density, cystic or solid appearance, calcification, capsule sign, enhancement pattern and metastases were assessed.
RESULTS: Fourteen women and seven men were identified with 12 being 25 years old or younger. Tumours were solitary and cystic-solid (76.2 %) masses with a capsule (76.2 %); 90.5 % were located in the medulla. Calcifications and lymph node metastases were each observed in 24 %. On unenhanced CT, tumour attenuation was greater than in normal renal parenchyma (85.7 %). Tumour enhancement was less than in normal renal cortex on all enhanced phases, greater than in normal renal medulla on cortical and medullary phases, but less than in normal renal medulla on delayed phase. On MR, the tumours were isointense on T1WI, heterogeneously hypointense on T2WI and slightly hyperintense on diffusion-weighted imaging.
CONCLUSION: Xp11.2/TFE RCC usually occurs in young women. It is a cystic-solid, hyperdense mass with a capsule. It arises from the renal medulla with enhancement less than in the cortex but greater than in the medulla in all phases except the delayed phase, when it is lower than in the medulla.
KEY POINTS: • Xp11.2/TFE RCC was more prevalent in young women. • On unenhanced CT, Xp11.2/TFE RCC attenuation was greater than in renal parenchyma. • Xp111/2TFE RCC arises primarily from the renal medulla. • Xp11.2/TFE RCC enhancement was less than in the cortex on all phases. • Enhancement was greater than in the medulla in arterial and corticomedullary phase.
Pivovarcikova K, Peckova K, Martinek P, et al."Mucin"-secreting papillary renal cell carcinoma: clinicopathological, immunohistochemical, and molecular genetic analysis of seven cases.
Virchows Arch. 2016; 469(1):71-80 [PubMed
] Related Publications
Mucin and mucin-like material are features of mucinous tubular and spindle renal cell carcinoma (MTS RCC) but are rarely seen in papillary renal cell carcinoma (PRCC). We reviewed 1311 PRCC and identified 7 tumors containing extracellular and/or intracellular mucinous/mucin-like material (labeled as PRCCM). We analyzed these using morphological, histochemical, immunohistochemical, and molecular genetic methods (arrayCGH, FISH). Clinical data were available for six of the seven patients (five males and one female, age range 61-78 years). Follow-up was available for four patients (2-4 years); one patient died of widespread metastases. Tumor size ranged from 3 to 5 cm (mean 3.8). Of all cases, histological architecture showed a predominantly papillary pattern. Mucin or mucin-like was extracellular in one, intracellular in three, and both intra/extracellular in three cases. All tumors were positive for AMACR, vimentin, and OSCAR, while CK7 was positive in four. Mucicarmine stain was positive in all cases, PAS in six and Alcian blue in three cases. Five tumors were positive for MUC 1, but none were positive for MUC 2, MUC 4, or MUC 6. In only four cases, genetic analysis could be performed. Gain of chromosomes 7 and 17 was found in two cases; gain of 17 only was found in one case. Loss of heterozygosity of 3p was found in one case together with polysomy of chromosomes 7 and 17. No abnormalities of VHL, fumarate dehydrogenase, and TFE3 genes were detected. We conclude that PRCCM is a rare but challenging subtype of RCC that deserves to be further studied. In all the tumors, the mucin-like material was found in those stained with mucicarmin, but other conventional and immunohistochemical stains did not reveal consistent features of a single mucin. The molecular-genetic profile of these tumors was most consistent with that of typical papillary RCC, although one case had mixed genetic features of papillary and clear RCC. PRCCM has metastatic potential, as evidenced by one case with widespread metastases. It remains to be determined whether PRCCM represents a unique tumor subtype, deserving to be distinguished from other subtypes of PRCC.
Just PA, Letourneur F, Pouliquen C, et al.Identification by FFPE RNA-Seq of a new recurrent inversion leading to RBM10-TFE3 fusion in renal cell carcinoma with subtle TFE3 break-apart FISH pattern.
Genes Chromosomes Cancer. 2016; 55(6):541-8 [PubMed
] Related Publications
Gene fusions involving TFE3 defines the "Xp11.2 translocations" subclass of renal cell carcinomas (RCCs) belonging to the MiT family translocation RCC. Four recurrent TFE3 fusion partners were identified to date: PRCC, ASPSCR1, SFPQ, and NONO. Break-apart TFE3 fluorescence in situ hybridization (FISH) on formalin-fixed and paraffin-embedded (FFPE) tissue sections is currently the gold standard for identification of TFE3 rearrangements. Herein, we report a case of RCC with a morphological appearance of Xp11.2 translocation, and positive TFE3 immunostaining. By FISH, the spots constituting the split signal were barely spaced, suggestive of a chromosome X inversion rather than a translocation. We performed RNA-seq from FFPE material to test this hypothesis. RNA-seq suggested a fusion of RBM10 gene exon 17 (Xp11.23) with TFE3 gene exon 5 (Xp11.2). RBM10-TFE3 fusion transcript was confirmed using specific RT-PCR. Our work showed that RNA-Seq is a robust technique to detect fusion transcripts from FFPE material. A RBM10-TFE3 fusion was previously described in single case of Xp11.2 RCC. Although rare, RBM10-TFE3 fusion variant (from chromosome X paracentric inversion), therefore, appears to be a recurrent molecular event in Xp11.2 RCCs. RBM10-TFE3 fusion should be added in the list of screened fusion transcripts in targeted molecular diagnostic multiplex RT-PCR. © 2016 Wiley Periodicals, Inc.
On the basis of multidimensional and comprehensive molecular characterization (including DNA methalylation and copy number, RNA, and protein expression), we classified 894 renal cell carcinomas (RCCs) of various histologic types into nine major genomic subtypes. Site of origin within the nephron was one major determinant in the classification, reflecting differences among clear cell, chromophobe, and papillary RCC. Widespread molecular changes associated with TFE3 gene fusion or chromatin modifier genes were present within a specific subtype and spanned multiple subtypes. Differences in patient survival and in alteration of specific pathways (including hypoxia, metabolism, MAP kinase, NRF2-ARE, Hippo, immune checkpoint, and PI3K/AKT/mTOR) could further distinguish the subtypes. Immune checkpoint markers and molecular signatures of T cell infiltrates were both highest in the subtype associated with aggressive clear cell RCC. Differences between the genomic subtypes suggest that therapeutic strategies could be tailored to each RCC disease subset.
Epithelioid hemangioendotheliomas (EHEs) are vascular tumors of intermediate malignancy that can undergo high-grade malignant transformations. EHEs have been characterized by tumor-specific WW domain-containing transcription regulator 1(WWTR1)-calmodulin-binding transcription activator 1 (CAMTA1) translocations, and recently, a novel Yes-associated protein 1 (YAP1)-transcription factor E3 (TFE3) gene fusion was identified in EHEs. In this study, we examined the expression levels of TFE3 and CAMTA1 via immunohistochemical staining and identified chromosomal alterations using fluorescence in situ hybridization (FISH) assays and RT-PCR tests. Although all of the EHEs were CAMTA1-positive in immunohistochemical staining, only five out of 18 EHEs (27.78%) positively expressed nuclear TFE3. The five TFE3-positive EHEs exhibited TFE3 gene break-apart in FISH assays. YAP1-TFE3 gene fusions were confirmed by RT-PCR. Interestingly, we observed CAMTA1 gene break-apart in all of the five TFE3-positive EHEs via FISH assays, and four out of the five TFE3-positive EHEs exhibited WWTR1-CAMTA1 gene fusions via RT-PCR. These results indicate that these two chromosomal alterations are not mutually exclusive but compossible in EHEs. Finally, primary tumor sites in TFE3-positive EHEs consistently contained single masses (P = 0.0359) with larger sizes (P = 0.0550) compared to TFE3-negative EHEs. Similar to previous reports, we observed well-formed vessels more frequently in TFE3-positive EHEs than in TFE3-negative EHEs (P = 0.0441). In addition, TFE3-positive EHEs tended to more frequently demonstrate high-grade nuclear atypia (P = 0.0654) and hypercellularity (P=0.0987) than TFE3-negative EHEs. Thus, we have now established two clinically distinct subgroups of EHEs: TFE3-positive and TFE3-negative EHEs.
Cajaiba MM, Jennings LJ, Rohan SM, et al.ALK-rearranged renal cell carcinomas in children.
Genes Chromosomes Cancer. 2016; 55(5):442-51 [PubMed
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Knowledge of the clinicopathological and molecular spectrum of pediatric renal cell carcinomas (RCC) remains limited, and approximately 16%-24% of these neoplasms cannot be classified into specific subtypes. In this review of 168 pediatric RCC prospectively registered on Children's Oncology Group AREN03B2 protocol, six RCC (3.5%) that demonstrated a unique epithelioid morphology and a peculiar immunophenotypic profile that includes expression of ALK, TFE3, and retention of INI1 was identified. Further investigation revealed ALK rearrangements in all cases, manifested molecularly by fusion transcripts of either VCL-ALK (3 patients all with sickle cell trait which had been previously reported) or TPM3-ALK (3 patients, none with sickle cell trait). Based on the shared unique morphologic, immunophenotypic, and genetic features, it was proposed that these neoplasms belonged to a distinct subgroup of RCC frequently occurring in pediatric patients, which they have termed as ALK-rearranged RCC. Importantly, additional therapeutic options may be available for these patients.
Enabled by high-throughput sequencing approaches, epithelial cancers across a range of tissue types are seen to harbor gene fusions as integral to their landscape of somatic aberrations. Although many gene fusions are found at high frequency in several rare solid cancers, apart from fusions involving the ETS family of transcription factors which have been seen in approximately 50% of prostate cancers, several other common solid cancers have been shown to harbor recurrent gene fusions at low frequencies. On the other hand, many gene fusions involving oncogenes, such as those encoding ALK, RAF or FGFR kinase families, have been detected across multiple different epithelial carcinomas. Tumor-specific gene fusions can serve as diagnostic biomarkers or help define molecular subtypes of tumors; for example, gene fusions involving oncogenes such as ERG, ETV1, TFE3, NUT, POU5F1, NFIB, PLAG1, and PAX8 are diagnostically useful. Tumors with fusions involving therapeutically targetable genes such as ALK, RET, BRAF, RAF1, FGFR1-4, and NOTCH1-3 have immediate implications for precision medicine across tissue types. Thus, ongoing cancer genomic and transcriptomic analyses for clinical sequencing need to delineate the landscape of gene fusions. Prioritization of potential oncogenic "drivers" from "passenger" fusions, and functional characterization of potentially actionable gene fusions across diverse tissue types, will help translate these findings into clinical applications. Here, we review recent advances in gene fusion discovery and the prospects for medicine.
PURPOSE: To compare the differences of CT characteristics between renal cell carcinomas (RCCs) associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 RCCs) and papillary cell renal cell carcinomas (PRCCs).
METHODS: CT images and clinical records of 64 patients (25 Xp11.2 RCCs, 15 type 1 and 24 type 2 PRCCs) were analyzed and compared retrospectively.
RESULTS: Xp11.2 RCC more frequently affected young (30.7 ± 8.7 years) women (16/25, 64%) with gross hematuria (12/25, 48%), while PRCC more frequently involved middle-aged (54.8 ± 11.1 years) men (28/39, 71.8%) asymptomatically. Xp11.2 RCC tended to be heterogeneous density with some showing circular calcification. Lesion sizes of Xp11.2 RCC (5.4 ± 2.2 cm) and type 2 PRCC (5.7 ± 2.5 cm) were significantly larger than that of type 1 PRCC (3.8 ± 1.8 cm). Xp11.2 RCC contained more cystic components (22/25, 88%) than type 1 PRCC (all solid) and type 2 PRCC (9/24, 36.0%). Type 1 PRCC (13/15, 86.7%) and Xp11.2 RCC (21/25, 84.0%) showed more clear boundary than type 2 PRCC (12/24, 50.0%).
CONCLUSION: CT features including diameter, boundary, attenuation, nature, and circular calcification of the tumor, combined with demographic information and symptoms, may be useful to differentiate Xp11.2 RCC from different subtypes of PRCC.
BACKGROUND: Papillary renal-cell carcinoma, which accounts for 15 to 20% of renal-cell carcinomas, is a heterogeneous disease that consists of various types of renal cancer, including tumors with indolent, multifocal presentation and solitary tumors with an aggressive, highly lethal phenotype. Little is known about the genetic basis of sporadic papillary renal-cell carcinoma, and no effective forms of therapy for advanced disease exist.
METHODS: We performed comprehensive molecular characterization of 161 primary papillary renal-cell carcinomas, using whole-exome sequencing, copy-number analysis, messenger RNA and microRNA sequencing, DNA-methylation analysis, and proteomic analysis.
RESULTS: Type 1 and type 2 papillary renal-cell carcinomas were shown to be different types of renal cancer characterized by specific genetic alterations, with type 2 further classified into three individual subgroups on the basis of molecular differences associated with patient survival. Type 1 tumors were associated with MET alterations, whereas type 2 tumors were characterized by CDKN2A silencing, SETD2 mutations, TFE3 fusions, and increased expression of the NRF2-antioxidant response element (ARE) pathway. A CpG island methylator phenotype (CIMP) was observed in a distinct subgroup of type 2 papillary renal-cell carcinomas that was characterized by poor survival and mutation of the gene encoding fumarate hydratase (FH).
CONCLUSIONS: Type 1 and type 2 papillary renal-cell carcinomas were shown to be clinically and biologically distinct. Alterations in the MET pathway were associated with type 1, and activation of the NRF2-ARE pathway was associated with type 2; CDKN2A loss and CIMP in type 2 conveyed a poor prognosis. Furthermore, type 2 papillary renal-cell carcinoma consisted of at least three subtypes based on molecular and phenotypic features. (Funded by the National Institutes of Health.).
Multiple primary malignant neoplasms are rare entities in the clinical setting, but represent an important issue in the clinical management of patients since they could be expression of a genetic predisposition to malignancy. A high resolution genome wide array CGH led us to identify the first case of a de novo constitutional deletion confined to the FBXW7 gene, a well known tumor suppressor, in a patient with a syndromic phenotype characterized by focal segmental glomerulosclerosis and multiple primary early/atypical onset tumors, including Hodgkin's lymphoma, Wilms tumor and breast cancer. Other genetic defects may be associated with patient's phenotype. In this light, constitutional mutations at BRCA1, BRCA2, TP53, PALB2 and WT1 genes were excluded by performing sequencing and MLPA analysis; similarly, we ruled out constitutional abnormalities at the imprinted 11p15 region by methylation specific -MLPA assay. Our observations sustain the role of FBXW7 as cancer predisposition gene and expand the spectrum of its possible associated diseases.
BACKGROUND: Xp11.2 or TFE3 translocation renal cell carcinomas (RCC) and alveolar soft part sarcoma (ASPS) are characterized by chromosome translocations involving the Xp11.2 breakpoint resulting in transcription factor TFE3 gene fusions. The most common translocations documented in TFE3 RCCs are t(X;1) (p11.2;q21) and t(X;17) (p11.2;q25) which leads to fusion of TFE3 gene on Xp11.2 with PRCC or ASPL respectively. TFE3 immunohistochemistry (IHC) has been inconsistent over time due to background staining problems in part related to fixation issues. Karyotyping to detect TFE3 gene rearrangement requires typically unavailable fresh tissue. Reverse transcriptase-polymerase chain reaction (RT-PCR) is generally very challenging due to degradation of RNA in archival material. The study objective was to develop and validate a TFE3 break-apart fluorescence in situ hybridization (FISH) assay to confirm Xp11 translocation RCCs and ASPS.
METHODS: Representative sections of formalin-fixed paraffin-embedded tissue blocks were selected in 40 possible cases. Approximately 60 tumor cells were analyzed in the targeted region. The validation of TFE3 FISH was done with 11 negative and two positive cases. Cut off for a positive result was validated as >7.15 % positive nuclei with any pattern of break-apart signals. FISH evaluation was done blinded of the immunohistochemical or karyotype data.
RESULTS: Three out of forty cases were positive for the TFE3 break-apart signals by FISH. The negative cases were reported as clear cell RCC with papillary features (10), clear cell RCC with sarcomatoid areas (2), Papillary RCC with clear cell areas (9), Chromophobe RCC (2), RCC, unclassified type (3) and renal medullary carcinoma (1). 3 of the negative cases were consultation cases for renal tumor with unknown histology. Seven negative cases were soft tissue tumor suspicious for ASPS.
CONCLUSION: Our study validates the utility of TFE3 break-apart FISH on formalin-fixed paraffin-embedded tissue sections for diagnosis and confirmation of Xp11.2 translocation RCCs and ASPS.
Magers MJ, Udager AM, Mehra RMiT Family Translocation-Associated Renal Cell Carcinoma: A Contemporary Update With Emphasis on Morphologic, Immunophenotypic, and Molecular Mimics.
Arch Pathol Lab Med. 2015; 139(10):1224-33 [PubMed
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Translocation-associated renal cell carcinoma (t-RCC) is a relatively uncommon subtype of renal cell carcinoma characterized by recurrent gene rearrangements involving the TFE3 or TFEB loci. TFE3 and TFEB are members of the microphthalmia transcription factor (MiT) family, which regulates differentiation in melanocytes and osteoclasts, and MiT family gene fusions activate unique molecular programs that can be detected immunohistochemically. Although the overall clinical behavior of t-RCC is variable, emerging molecular data suggest the possibility of targeted approaches to advanced disease. Thus, distinguishing t-RCC from its morphologic, immunophenotypic, and molecular mimics may have important clinical implications. The differential diagnosis for t-RCC includes a variety of common renal neoplasms, particularly those demonstrating clear cell and papillary features; in addition, because of immunophenotypic overlap and/or shared molecular abnormalities (ie, TFE3 gene rearrangement), a distinctive set of nonepithelial renal tumors may also warrant consideration. Directed ancillary testing is an essential aspect to the workup of t-RCC cases and may include a panel of immunohistochemical stains, such as PAX8, pancytokeratins, epithelial membrane antigen, carbonic anhydrase IX, HMB-45, and Melan-A. Dual-color, break-apart fluorescent in situ hybridization for TFE3 or TFEB gene rearrangement may be helpful in diagnostically challenging cases or when molecular confirmation is needed.
Doyle LA, Fletcher CD, Hornick JLNuclear Expression of CAMTA1 Distinguishes Epithelioid Hemangioendothelioma From Histologic Mimics.
Am J Surg Pathol. 2016; 40(1):94-102 [PubMed
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Epithelioid hemangioendothelioma (EHE) is a malignant endothelial neoplasm characterized by recurrent translocations involving chromosomal regions 1p36.3 and 3q25, resulting in the formation of a WWTR1-CAMTA1 fusion gene in approximately 90% of cases; a small subset (<5%) have a YAP1-TFE3 fusion gene. The WWTR1-CAMTA1 fusion gene leads to overexpression of both genes. WWTR1 protein is expressed in many different cell types, whereas CAMTA1 expression is normally limited to the brain. A prior study using a polyclonal antibody directed against regions within the C-terminus of CAMTA1 reported widespread expression in both normal tissues and diverse tumor types. In contrast, a recent study using a different polyclonal antibody directed against the C-terminus of CAMTA1 suggested that this other antibody is a potentially useful diagnostic marker for EHE. Our study aimed to validate this finding in a large series of EHE cases and to determine whether CAMTA1 is expressed in other epithelioid mesenchymal tumors that may mimic EHE. Protein expression of CAMTA1 was evaluated in whole-tissue sections of 204 tumors using a polyclonal anti-CAMTA1 antibody: 59 EHE (48 conventional, 11 "malignant"; 4 with known TFE3 gene rearrangement); 70 other epithelioid vascular tumors; and 75 nonendothelial epithelioid mesenchymal neoplasms. In total, 51/59 cases (86%) of EHE showed diffuse nuclear staining for CAMTA1, including 44/48 cases (92%) with conventional histology and 7/11 cases (64%) with "malignant" histology. Of the 8 CAMTA1-negative tumors, 6 were positive for TFE3. With the exception of 1 case previously diagnosed as epithelioid angiosarcoma on core biopsy, all other tumor types examined were negative for CAMTA1. In conclusion, in keeping with the reported frequency of WWTR1-CAMTA1 in EHE, nuclear CAMTA1 expression is identified in the majority of EHE cases, whereas other epithelioid mesenchymal neoplasms are negative for CAMTA1. These findings support the diagnostic utility of immunohistochemistry for CAMTA1 in distinguishing EHE from histologic mimics, in particular benign epithelioid vascular tumors, epithelioid angiosarcoma, and epithelioid sarcoma, an important distinction given the differences in biological potential and clinical course.
Shon W, Kim J, Sukov W, Reith JMalignant TFE3-rearranged perivascular epithelioid cell neoplasm (PEComa) presenting as a subcutaneous mass.
Br J Dermatol. 2016; 174(3):617-20 [PubMed
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Perivascular epithelioid cell neoplasms (PEComas) are a group of mesenchymal tumours with concurrent melanocytic and myogenic differentiation. Although many cases are sporadic, PEComas can be associated with tuberous sclerosis. A distinct subset of deep-seated PEComas has been shown to carry TFE3 fusions. To our knowledge, this is the first reported case of primary subcutaneous malignant PEComa with molecular confirmation of TFE3 gene rearrangement.
Zhao M, Rao Q, Wu C, et al.Alveolar soft part sarcoma of lung: report of a unique case with emphasis on diagnostic utility of molecular genetic analysis for TFE3 gene rearrangement and immunohistochemistry for TFE3 antigen expression.
Diagn Pathol. 2015; 10:160 [PubMed
] Free Access to Full Article Related Publications
Alveolar soft part sarcoma (ASPS) is a rare, malignant mesenchymal tumor of distinctive clinical, morphologic, ultrastructural, and cytogenetical characteristics. It typically arises in the extremities of adolescents and young adults, but has also been documented in a number of unusual sites, thus causing diagnostic confusions both clinically and morphologically. The molecular signature of ASPS is a specific der(17)t(X;17)(p11.2;q25) translocation, which results in the fusion of TFE3 transcription factor gene at Xp11.2 with ASPL at 17q25. Recent studies have shown that the ASPL-TFE3 fusion transcript can be identified by reverse-transcriptase polymerase chain reaction analysis and TFE3 gene rearragement can be detected using a dual-color, break apart fluorescence in situ hybridization assay in paraffin-embedded tissue, and the resultant fusion protein can be detected immunohistochemically with antibody directed to the carboxy terminal portion of TFE3. Herein, we report a unique case of ASPS presenting as an asymptomatic mass in the lung of a 48 year-old woman without evidence of a primary soft tissue tumor elsewhere at the time of initial diagnosis. To the best of our knowledge, this is the third report of such cases appearing in the English language literature to date. We emphasize the differential diagnoses engendered by ASPS including a series of tumors involving the lung that have nested and alveolar growth patterns, and both clear and eosinophilic cytoplasm, and demonstrate the utility of molecular genetic analysis for TFE3 rearrangement and immunohistochemistry for TFE3 antigen expression for arriving at accurate diagnosis.
Birt-Hogg-Dubé (BHD) syndrome is an inherited renal cancer syndrome in which affected individuals are at risk of developing benign cutaneous fibrofolliculomas, bilateral pulmonary cysts and spontaneous pneumothoraces, and kidney tumours. Bilateral multifocal renal tumours that develop in BHD syndrome are most frequently hybrid oncocytic tumours and chromophobe renal carcinoma, but can present with other histologies. Germline mutations in the FLCN gene on chromosome 17 are responsible for BHD syndrome--BHD-associated renal tumours display inactivation of the wild-type FLCN allele by somatic mutation or chromosomal loss, confirming that FLCN is a tumour suppressor gene that fits the classic two-hit model. FLCN interacts with two novel proteins, FNIP1 and FNIP2, and with AMPK, a negative regulator of mTOR. Studies with FLCN-deficient cell and animal models support a role for FLCN in modulating the AKT-mTOR pathway. Emerging evidence links FLCN with a number of other molecular pathways and cellular processes important for cell homeostasis that are frequently deregulated in cancer, including regulation of TFE3 and/or TFEB transcriptional activity, amino-acid-dependent mTOR activation through Rag GTPases, TGFβ signalling, PGC1α-driven mitochondrial biogenesis, and autophagy. Currently, surgical intervention is the only therapy available for BHD-associated renal tumours, but improved understanding of the FLCN pathway will hopefully lead to the development of effective forms of targeted systemic therapy for this disease.
Rao Q, Shen Q, Xia QY, et al.PSF/SFPQ is a very common gene fusion partner in TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas) and melanotic Xp11 translocation renal cancers: clinicopathologic, immunohistochemical, and molecular characteristics suggesting classification as a distinct entity.
Am J Surg Pathol. 2015; 39(9):1181-96 [PubMed
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An increasing number of TFE3 rearrangement-associated tumors, such as TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas), melanotic Xp11 translocation renal cancers, and melanotic Xp11 neoplasms, have recently been reported. We examined 12 such cases, including 5 TFE3 rearrangement-associated PEComas located in the pancreas, cervix, or pelvis and 7 melanotic Xp11 translocation renal cancers, using clinicopathologic, immunohistochemical, and molecular analyses. All the tumors shared a similar morphology, including a purely nested or sheet-like architecture separated by a delicate vascular network, purely epithelioid cells displaying a clear or granular eosinophilic cytoplasm, a lack of papillary structures and spindle cell or fat components, uniform round or oval nuclei containing small visible nucleoli, and, in most cases (11/12), melanin pigmentation. The levels of mitotic activity and necrosis varied. All 12 cases displayed moderately (2+) or strongly (3+) positive immunoreactivity for TFE3 and cathepsin K. One case labeled focally for HMB45 and Melan-A, whereas the others typically labeled moderately (2+) or strongly (3+) for 1 of these markers. None of the cases were immunoreactive for smooth muscle actin, desmin, CKpan, S100, or PAX8. PSF-TFE3 fusion genes were confirmed by reverse transcription polymerase chain reaction in cases (7/7) in which a novel PSF-TFE3 fusion point was identified. All of the cases displayed TFE3 rearrangement associated with Xp11 translocation. Furthermore, we developed a PSF-TFE3 fusion fluorescence in situ hybridization assay for the detection of the PSF-TFE3 fusion gene and detected it in all 12 cases. Clinical follow-up data were available for 7 patients. Three patients died, and 2 patients (cases 1 and 3) remained alive with no evidence of disease after initial resection. Case 2 experienced recurrence and remained alive with disease. Case 5, a recent case, remained alive with extensive abdominal cavity metastases. Our data suggest that these tumors belong to a single clinicopathologic spectrum and expand the known characteristics of TFE3 rearrangement-associated tumors.
OBJECTIVES: To evaluate the feasibility and efficacy of tumor enucleation (TE) for patients with small renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) by analyzing the pseudocapsule characteristics of Xp11.2 RCCs comparing with that of clear cell renal cell carcinoma (ccRCC).
METHODS: From June 2007 to February 2014, 22 patients with Xp11.2 RCC who were diagnosed by fluorescence in-situ hybridization polyclonal (FISH) assay and 32 patients with ccRCC treated in our institution were comparatively studied. 12 patients with ccRCC underwent radical nephrectomy (RN) and 20 received TE. Among 22 patients with Xp11.2 RCC, 19 were treated by RN and 3 by TE (1 by radiofrequency ablation assisted TE). Pseudocapsule and other clinicopathological characteristics of the two subtypes of RCC were compared. Survival of patients treated with different surgical methods was evaluated and compared.
RESULTS: Pseudocapsule incidence of Xp11.2 RCC (14/22, 63.6%) was lower than that of ccRCC (32/32, 100%, P<0.001). However, pseudocapsule integrity rate of Xp11.2 RCC (10/14, 71.4%) was comparable with that of ccRCC (23/32, 71.9%, P=1.000). The 5-year overall survival of patients with ccRCC treated with RN and TE was 86% and 81%, respectively (P=0.845). Three patients with small Xp11.2 RCC performed well after TE.
CONCLUSIONS: Over half Xp11.2 RCC had pseudocapsules, whose integrity rate was comparable to that of ccRCC. Treatment effectives of TE and RN were comparable in ccRCC. A preliminary attempt to treat small Xp11.2 RCC with intact pseudocapsule by using TE produced a favorable treatment outcome.
He J, Chen X, Gan W, et al.Renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions: clinical experience and literature review.
Future Oncol. 2015; 11(24):3243-52 [PubMed
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AIM: To analyze the clinicopathological features of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusions (Xp11.2 RCC) in our institution.
MATERIALS & METHODS: We screened 983 RCC specimens. TFE3 immunohistochemical staining and FISH assay confirmed 22 Xp11.2 RCCs out of 65 suspicious cases. Clinicopathological and treatment outcomes of 22 patients were retrospectively analyzed.
RESULTS: In total, 22 patients included 13 females and nine males with a mean age of 27 years. Ten patients showed gross hematuria. Treatments included surgeries, immunotherapy and molecular-targeted therapy. Seven cases were at stage III/IV and four cases had tumor thrombosis or distant metastasis. During a median follow-up of 34 months, 19 patients were alive while three died of distant metastasis.
CONCLUSION: Xp11.2 RCC is rare and FISH proved a useful diagnostic tool. Surgical resection achieved favorable outcome for early disease. Adult patients at advanced stage had poorer outcomes even with postoperative adjuvant therapy.
Activation of cellular stress response pathways to maintain metabolic homeostasis is emerging as a critical growth and survival mechanism in many cancers. The pathogenesis of pancreatic ductal adenocarcinoma (PDA) requires high levels of autophagy, a conserved self-degradative process. However, the regulatory circuits that activate autophagy and reprogram PDA cell metabolism are unknown. Here we show that autophagy induction in PDA occurs as part of a broader transcriptional program that coordinates activation of lysosome biogenesis and function, and nutrient scavenging, mediated by the MiT/TFE family of transcription factors. In human PDA cells, the MiT/TFE proteins--MITF, TFE3 and TFEB--are decoupled from regulatory mechanisms that control their cytoplasmic retention. Increased nuclear import in turn drives the expression of a coherent network of genes that induce high levels of lysosomal catabolic function essential for PDA growth. Unbiased global metabolite profiling reveals that MiT/TFE-dependent autophagy-lysosome activation is specifically required to maintain intracellular amino acid pools. These results identify the MiT/TFE proteins as master regulators of metabolic reprogramming in pancreatic cancer and demonstrate that transcriptional activation of clearance pathways converging on the lysosome is a novel hallmark of aggressive malignancy.
Thway K, Fisher CPEComa: morphology and genetics of a complex tumor family.
Ann Diagn Pathol. 2015; 19(5):359-68 [PubMed
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Perivascular epithelioid cell tumors, or PEComas, are mesenchymal neoplasms composed of histologically and immunohistochemically distinctive epithelioid or spindle cells, which are immunoreactive for both smooth muscle and melanocytic markers. The cells in PEComas are typically arranged around blood vessels and appear to form the vessel wall, often infiltrating the smooth muscle of small- to medium-sized vessels. Periluminal cells are usually epithelioid and the more peripheral cells are spindle shaped. The cells have small, round to oval nuclei, sometimes with focal nuclear atypia, and clear to eosinophilic cytoplasm, and no counterpart normal cell has been identified. The PEComa "family" now includes angiomyolipoma, pulmonary clear cell "sugar" tumor and lymphangioleiomyomatosis, primary extrapulmonary sugar tumor, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, abdominopelvic sarcoma of perivascular epithelioid cells, and other tumors with similar features at various sites that are simply termed PEComa. Some PEComas occur in patients with tuberous sclerosis complex and share the genetic abnormalities. There is a behavioral spectrum from benign to frankly malignant, and histologic criteria have been proposed for assessing malignant potential. The differential diagnosis can include carcinomas, smooth muscle tumors, other clear cell neoplasms, and adipocytic tumors. PEComas constitute a genetically diverse group that includes neoplasms harboring TFE3 gene rearrangements and those with TSC2 mutations, indicating alternative tumorigenic pathways. Recent advances in therapy of malignant PEComas relate to increased knowledge of specific genetic changes and their effects on metabolic pathways that are susceptible to specific interventions. We review PEComas, emphasizing the diagnostic spectrum and recent immunohistochemical and genetic findings.
Mohamed AD, Tremblay AM, Murray GI, Wackerhage HThe Hippo signal transduction pathway in soft tissue sarcomas.
Biochim Biophys Acta. 2015; 1856(1):121-9 [PubMed
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Sarcomas are rare cancers (≈1% of all solid tumours) usually of mesenchymal origin. Here, we review evidence implicating the Hippo pathway in soft tissue sarcomas. Several transgenic mouse models of Hippo pathway members (Nf2, Mob1, LATS1 and YAP1 mutants) develop various types of sarcoma. Despite that, Hippo member genes are rarely point mutated in human sarcomas. Instead, WWTR1-CAMTA1 and YAP1-TFE3 fusion genes are found in almost all cases of epithelioid haemangioendothelioma. Also copy number gains of YAP1 and other Hippo members occur at low frequencies but the most likely cause of perturbed Hippo signalling in sarcoma is the cross-talk with commonly mutated cancer genes such as KRAS, PIK3CA, CTNNB1 or FBXW7. Current Hippo pathway-targeting drugs include compounds that target the interaction between YAP and TEAD G protein-coupled receptors (GPCR) and the mevalonate pathway (e.g. statins). Given that many Hippo pathway-modulating drugs are already used in patients, this could lead to early clinical trials testing their efficacy in different types of sarcoma.
TFE3 translocation renal cell carcinoma is a highly aggressive malignancy which often occurs primarily in children and young adults. The pathognomonic molecular lesion in this subtype is a translocation event involving the TFE3 transcription factor at chromosome Xp11.2. Hence, the pathological diagnosis of an Xp11.2 translocation RCC is based upon morphology, TFE3 immunohistochemistry, or genetic analyses. However, due to the false-positive immunoreactivity for TFE3 IHC and expensive for TFE3 break-apart FISH assay, additional molecular markers are necessary to help provide early diagnose and individualization treatment. Owing to recent advances in microarray and RNA-Seq, Pflueger et al. have discovered that TMED6-COG8 is dramatically increased in TFE3 translocation RCCs, compared with clear cell RCCs and papillary RCCs, implying that TMED6-COG8 might be a new molecular tumor marker of TFE3 translocation RCCs. To extend this observation, we firstly validated the TMED6-COG8 expression level by qRT-PCR in RCCs including Xp11.2 translocation RCCs (n=5), clear cell RCCs (n=7) and papillary RCCs (n=5). Then, we also examined the expression level of TMED6-COG8 chimera in Xp11.2 translocation alveolar soft part sarcoma. We found that TMED6-COG8 chimera expression level was higher in Xp11.2 translocation RCCs than in ASPS (P<0.05). What's more, the expression levels of TMED6-COG8 chimera in esophagus cancers (n=32), gastric cancers (n=11), colorectal cancers (n=12), hepatocellular carcinomas (n=10) and non-small-cell lung cancers (n=12) were assessed. Unexpectedly, TMED6-COG8 chimera was decreased in these five human types. Therefore, our observations from this study indicated that TMED6-COG8 chimera might act as a novel diagnostic marker in Xp11.2 translocation RCCs.
Ploper D, De Robertis EMThe MITF family of transcription factors: Role in endolysosomal biogenesis, Wnt signaling, and oncogenesis.
Pharmacol Res. 2015; 99:36-43 [PubMed
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Canonical Wnt signaling influences cellular fate and proliferation through inhibition of Glycogen Synthase Kinase (GSK3) and the subsequent stabilization of its many substrates, most notably β-Catenin, a transcriptional co-activator. MITF, a melanoma oncogene member of the microphthalmia family of transcription factors (MiT), was recently found to contain novel GSK3 phosphorylation sites and to be stabilized by Wnt. Other MiT members, TFEB and TFE3, are known to play important roles in cellular clearance pathways by transcriptionally regulating the biogenesis of lysosomes and autophagosomes via activation of CLEAR elements in gene promoters of target genes. Recent studies suggest that MITF can also upregulate many lysosomal genes. MiT family members are dysregulated in cancer and are considered oncogenes, but the underlying oncogenic mechanisms remain unclear. Here we review the role of MiT members, including MITF, in lysosomal biogenesis, and how cancers overexpressing MITF, TFEB or TFE3 could rewire the lysosomal pathway, inhibit cellular senescence, and activate Wnt signaling by increasing sequestration of negative regulators of Wnt signaling in multivesicular bodies (MVBs). Microarray studies suggest that MITF expression inhibits macroautophagy. In melanoma the MITF-driven increase in MVBs generates a positive feedback loop between MITF, Wnt, and MVBs.
Chen X, Yang Y, Gan W, et al.Newly designed break-apart and ASPL-TFE3 dual-fusion FISH assay are useful in diagnosing Xp11.2 translocation renal cell carcinoma and ASPL-TFE3 renal cell carcinoma: a STARD-compliant article.
Medicine (Baltimore). 2015; 94(19):e873 [PubMed
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The diagnosis of Xp11.2 translocation renal cell carcinoma (tRCC), which relies on morphology and immunohistochemistry (IHC), is often either missed in the diagnosis or misdiagnosed. To improve the accuracy of diagnosis of Xp11.2 tRCC and ASPL-TFE3 renal cell carcinoma (RCC), we investigated newly designed fluorescence in situ hybridization (FISH) probes (diagnostic accuracy study).Based on the genetic characteristics of Xp11.2 tRCC and the ASPL-TFE3 RCC, a new break-apart TFE3 FISH probe and an ASPL-TFE3 dual-fusion FISH probe were designed and applied to 65 patients with RCC who were <45 years old or showed suspicious microscopic features of Xp11.2 tRCC in our hospital. To test the accuracy of the probes, we further performed reverse transcriptase-polymerase chain reaction (PCR) on 8 cases for which frozen tissues were available.Among the 65 cases diagnosed with RCC, TFE3 IHC was positive in 24 cases. Twenty-two cases were confirmed as Xp11.2 tRCC by break-apart TFE3 FISH, and 6 of these cases were further diagnosed as ASPL-TFE3 RCC by ASPL-TFE3 dual-fusion FISH detection. Importantly, reverse transcriptase-PCR showed concordant results with the results of FISH assay in the 8 available frozen cases.The break-apart and ASPL-TFE3 dual-fusion FISH assay can accurately detect the translocation of the TFE3 gene and ASPL-TFE3 fusion gene and can thus serve as a valid complementary method for diagnosing Xp11.2 tRCC and ASPL-TFE3 RCC.
Kuroda N, Agatsuma Y, Tamura M, et al.Sporadic renal hemangioblastoma with CA9, PAX2 and PAX8 expression: diagnostic pitfall in the differential diagnosis from clear cell renal cell carcinoma.
Int J Clin Exp Pathol. 2015; 8(2):2131-8 [PubMed
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To date, 13 cases of sporadic renal hemangioblastoma have been reported. In this article, we report such a case that might cause the diagnostic pitfall. A 37-year-old Japanese was found to have a renal mass by periodic medical check-up. He underwent radical nephrectomy. Macroscopically, the tumor was well-defined without fibrous capsule and the cut surface of the tumor exhibited light brown to gray-tan color without hemorrhage or necrosis. Microscopically, the tumor was made up of large polygonal to short spindle cells with eosinophilic cytoplasm with occasional vacuolization and abundant arborizing capillary network. Immunohistochemically, neoplastic cells showed diffuse positivity for inhibin-alpha, S-100 protein, vimentin, CA9, PAX2 and PAX8, but negativity for cytokeratin CAM5.2, alpha smooth muscle actin, Melanosome, Melan A, TFE3 and cathepsin K. In genetic analyses, this tumor showed no changes of VHL gene mutation, hypermethylation and loss of heterozygosity of chromosome 3p. Additionally, G-band karyotype and array comparative genomic hybridization studies showed a normal chromosome. In conclusion, the positivity for CA9, PAX2 and PAX8 in sporadic renal hemangioblastoma may cause the critical diagnostic pitfall in the differential diagnosis from clear cell renal cell carcinoma. Pathologists need to pay attention to systemic evaluation including macroscopic, microscopic and immunohistochemical findings. In some cases, molecular genetic study may be necessary.
Deml KF, Schildhaus HU, Compérat E, et al.Clear cell papillary renal cell carcinoma and renal angiomyoadenomatous tumor: two variants of a morphologic, immunohistochemical, and genetic distinct entity of renal cell carcinoma.
Am J Surg Pathol. 2015; 39(7):889-901 [PubMed
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Clear cell papillary renal cell carcinoma (ccpRCC) and renal angiomyoadenomatous tumor (RAT) share morphologic similarities with clear cell (ccRCC) and papillary RCC (pRCC). It is a matter of controversy whether their morphologic, immunophenotypic, and molecular features allow the definition of a separate renal carcinoma entity. The aim of our project was to investigate specific renal immunohistochemical biomarkers involved in the hypoxia-inducible factor pathway and mutations in the VHL gene to clarify the relationship between ccpRCC and RAT. We investigated 28 ccpRCC and 9 RAT samples by immunohistochemistry using 25 markers. VHL gene mutations and allele losses were investigated by Sanger sequencing and fluorescence in situ hybridization. Clinical follow-up data were obtained for a subset of the patients. No tumor recurrence or tumor-related death was observed in any of the patients. Immunohistochemistry and molecular analyses led to the reclassification of 3 tumors as ccRCC and TFE3 translocation carcinomas. The immunohistochemical profile of ccpRCC and RAT samples was very similar but not identical, differing from both ccRCC and pRCC. Especially, the parafibromin and hKIM-1 expression exhibited differences in ccpRCC/RAT compared with ccRCC and pRCC. Genetic analysis revealed VHL mutations in 2/27 (7%) and 1/7 (14%) ccpRCC and RAT samples, respectively. Fluorescence in situ hybridization analysis disclosed a 3p loss in 2/20 (10%) ccpRCC samples. ccpRCC and RAT have a specific morphologic and immunohistochemical profile, but they share similarities with the more aggressive renal tumors. On the basis of our results, we regard ccpRCC/RAT as a distinct entity of RCCs.
Aron M, Chang E, Herrera L, et al.Clear cell-papillary renal cell carcinoma of the kidney not associated with end-stage renal disease: clinicopathologic correlation with expanded immunophenotypic and molecular characterization of a large cohort with emphasis on relationship with renal angiomyoadenomatous tumor.
Am J Surg Pathol. 2015; 39(7):873-88 [PubMed
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Clear cell-papillary renal cell carcinoma (CC-Pap RCC) is a recently described renal tumor initially reported in the setting of end-stage renal disease (ESRD). It has unique morphologic and immunohistochemical features that differentiate it from the more common clear cell RCC and papillary RCC. Recently, these tumors have also been described in a sporadic setting. We studied 64 cases of CC-Pap RCC not associated with ESRD (57 CC-Pap RCCs and 7 cases with features of renal angiomyoadenomatous tumors [RAT] including 5 initially diagnosed as such). The morphologic features of all cases and the immunohistochemical profile of 59 cases were studied along with the clinical and molecular features of 30 and 12 cases, respectively. All the tumors were well circumscribed with a mean tumor size of 2.6 cm and showed a wide array of architectural patterns, usually mixed, including tubular (77%), papillary (62%), tubulocystic (52%), and compact nested (21%). Seventy-three percent of the cases showed areas in which the tumor nuclei had a distinct orientation away from the basement membrane. Ninety-two percent of the cases had a low Fuhrman nuclear grade (nuclear grade 2%-86%, and nuclear grade 1%-6%); however, 8% cases showed foci of Fuhrman nuclear grade 3. In 4 cases, epithelial tumor comprised <5% of the tumor; >95% of the tumor was cystic or hyalinized. The stroma varied from being minimal to occasionally prominent myxoid to hyalinized and rarely with organized amianthoid fibers or well-defined smooth muscle bundles. Pathologic stage was reliably assigned in 60 cases, of which 93.3% (56 cases) were pT1, 3.3% (2 cases) were pT2, and 3.3% (2 cases) were pT3a with extension into the perinephric fat. One case had coagulative necrosis; sarcomatoid change and vascular invasion was not identified. The tumors showed a fairly typical immunoprofile characterized by positivity for CK7 (100%), HMCK (96%), CAIX (94%), and vimentin (100%) with negativity for AMACR, RCC, and TFE3; CD10 was positive in 24%. None of the cases tested showed recurrent chromosomal imbalances by virtual karyotyping, fluorescence in situ hybridization, or 3p loss of heterozygosity analysis. VHL gene mutations were, however, noted in 3 cases (2 in exon 1 and 1 in exon 3). Clinical follow-up information was available in 47% of the patients, with a mean and median follow-up of 47 and 37 months, respectively (range, 18 to 108 mo). One case occurred in the setting of VHL syndrome and multiple benign cysts. None of the cases showed local recurrence, metastasis, or death due to disease. Morphology, immunophenotype, and molecular studies did not vary between typical cases, those with prominent smooth muscle (so-called RAT), and historically published data on cases occurring in ESRD. Our analysis confirms that CC-Pap RCC is a unique subtype of adult renal epithelial neoplasia in which tumors are frequently small, are of low nuclear grade and pathologic stage, and have extremely favorable short to intermediate range prognosis. Tumors occurring sporadically, with prominent smooth muscle stroma (so-called RAT), and occurring in ESRD are in the spectrum of the same category of tumors.