Xp11 Translocation Renal Cell Carcinomas (RCCs) With RBM10-TFE3 Gene Fusion Demonstrating Melanotic Features and Overlapping Morphology With t(6;11) RCC: Interest and Diagnostic Pitfall in Detecting a Paracentric Inversion of TFE3

Am J Surg Pathol. 2017 May;41(5):663-676. doi: 10.1097/PAS.0000000000000837.

Abstract

Xp11 translocation renal cell carcinomas (RCC) are characterized by several different translocations involving the TFE3 gene. Tumors with different specific gene fusions may have different clinicopathologic manifestations. Only 3 RBM10-TFE3 RCCs have been reported to date. Here, we added 4 cases of this rare type of tumors with clinicopathologic, immunohistochemical, molecular, and ultrastructural analyses. Most tumors had similar patterns with mixed architectures as follows: acinar, tubular and papillary patterns of epithelioid cells combined with sheets of small cells with "pseudorosette-like" architectures, mimicking the typical morphology of t(6;11) RCC. Cytoplasmic vacuolization, nuclear groove, and psammoma bodies were observed in most cases. Immunohistochemically, all 4 cases demonstrated moderate to strong immunoreactivity for TFE3, Cathepsin K, CD10, Ksp-cadherin, E-cadherin, P504S, RCC marker, PAX8 and vimentin, whereas negativity for TFEB, HMB45, and CK7. CKpan and Melan-A were at least focally expressed. The antibody to Ki-67 showed labeling of 3% to 8% (mean, 5%) of tumor cell nuclei. ;Of interest, several immunostainings demonstrated expression discrepancy in different histology patterns. RBM10-TFE3 fusion transcripts were identified in all cases by reverse transcription-polymerase chain reaction. By fluorescence in situ hybridization, all 4 cases showed unusual split signals with a distance <1 signal diameter (co-localized or subtle split signals) and usually had false-negative results. We also observed ultrastructures, including melanin pigment, nuclear groove, numerous glycogens, mitochondrion with areas of high electron density material, basement membrane material, and cell junctions with poor development. All 4 patients were alive with no evidence of recurrent disease. Our report adds to the known data regarding RBM10-TFE3 RCC.

Publication types

  • Multicenter Study

MeSH terms

  • Aged
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / analysis
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / genetics*
  • Biomarkers, Tumor* / analysis
  • Biomarkers, Tumor* / genetics
  • Carcinoma, Renal Cell / chemistry
  • Carcinoma, Renal Cell / genetics*
  • Carcinoma, Renal Cell / ultrastructure
  • Cathepsin K / analysis
  • China
  • Chromosome Inversion*
  • Chromosomes, Human, Pair 11*
  • Chromosomes, Human, Pair 6*
  • Chromosomes, Human, X*
  • Female
  • Gene Fusion*
  • Genetic Predisposition to Disease
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Kidney Neoplasms / chemistry
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / ultrastructure
  • Male
  • Melanins / analysis*
  • Middle Aged
  • Predictive Value of Tests
  • RNA-Binding Proteins / genetics*
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • Translocation, Genetic*

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Biomarkers, Tumor
  • Melanins
  • RBM10 protein, human
  • RNA-Binding Proteins
  • TFE3 protein, human
  • CTSK protein, human
  • Cathepsin K