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 Sep;39(9):1181-96. doi: 10.1097/PAS.0000000000000502.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • 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*
  • Child
  • Chromosomes, Human, X*
  • Female
  • Gene Fusion*
  • Gene Rearrangement*
  • Genetic Predisposition to Disease
  • Humans
  • Immunohistochemistry*
  • In Situ Hybridization, Fluorescence
  • Kidney Neoplasms / chemistry
  • Kidney Neoplasms / classification
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / mortality
  • Kidney Neoplasms / pathology
  • Male
  • Melanoma / chemistry
  • Melanoma / classification
  • Melanoma / genetics*
  • Melanoma / mortality
  • Melanoma / pathology
  • Middle Aged
  • Mitosis
  • Molecular Diagnostic Techniques*
  • PTB-Associated Splicing Factor
  • Perivascular Epithelioid Cell Neoplasms / chemistry
  • Perivascular Epithelioid Cell Neoplasms / classification
  • Perivascular Epithelioid Cell Neoplasms / genetics*
  • Perivascular Epithelioid Cell Neoplasms / mortality
  • Perivascular Epithelioid Cell Neoplasms / pathology
  • Phenotype
  • Predictive Value of Tests
  • Prognosis
  • RNA-Binding Proteins / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • Translocation, Genetic*

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Biomarkers, Tumor
  • PTB-Associated Splicing Factor
  • RNA-Binding Proteins
  • TFE3 protein, human