Renal cell carcinomas with t(6;11)(p21;q12): A clinicopathologic study emphasizing unusual morphology, novel alpha-TFEB gene fusion point, immunobiomarkers, and ultrastructural features, as well as detection of the gene fusion by fluorescence in situ hybridization

Am J Surg Pathol. 2012 Sep;36(9):1327-38. doi: 10.1097/PAS.0b013e31825aafb5.

Abstract

Renal cell carcinomas (RCCs) with t(6;11)(p21;q12) are extremely rare and characterized by specific chromosome translocation, involving the transcription factor EB (TFEB). Fewer than 30 cases have been described in the literature. We examined 7 additional cases of this rare tumor by clinicopathologic, immunohistochemical, molecular, and ultrastructural analyses. Four tumors had the typical morphologic features of TFEB RCCs, whereas 3 cases demonstrated uncommon morphologic features, mimicking epithelioid angiomyolipoma, chromophobe cell RCC, and clear cell RCC, respectively. Immunohistochemically, aside from TFEB and cathepsin K, kidney-specific cadherin was another sensitive and relatively specific marker for TFEB RCCs, supporting a distal nephron origin for these renal tumors. We also observed different ultrastructures including mitochondrion with areas of lipofuscin pigment in the smaller cells in these cases. An identical Alpha-TFEB fusion gene, 486 bp, was identified in 2 cases. In addition to the polymerase chain reaction method, we also developed a fluorescence in situ hybridization assay to serve as a cost-effective and time-efficient diagnostic tool. We detected a TFEB gene rearrangement in all 7 cases using the fluorescence in situ hybridization method. TFEB RCC seemed to be an indolent tumor. During a mean follow-up of 31 months, none of the cases developed tumor recurrence, progression, or metastasis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism
  • Biomarkers, Tumor / metabolism
  • Carcinoma, Renal Cell / genetics*
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • Chromosomes, Human, Pair 11 / genetics*
  • Chromosomes, Human, Pair 6 / genetics*
  • DNA, Neoplasm / analysis
  • Female
  • Gene Fusion
  • Gene Rearrangement
  • Humans
  • In Situ Hybridization, Fluorescence / methods
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Male
  • Nephrectomy
  • Translocation, Genetic*
  • Treatment Outcome
  • Young Adult

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Biomarkers, Tumor
  • DNA, Neoplasm
  • TFEB protein, human