Primary paranasal sinus clear cell carcinoma with EWSR1-ATF1 fusion: report of 2 molecularly confirmed cases exhibiting unique histopathology

Hum Pathol. 2017 May:63:139-143. doi: 10.1016/j.humpath.2016.09.036. Epub 2016 Dec 1.

Abstract

Hyalinizing clear cell carcinoma (HCCC) is a rare low-grade tumor of the salivary glands made up of clear cells that form cords and nests in hyalinized stroma. To date, primary HCCCs of the paranasal sinus have not been described. This article presents 2 cases of HCCC of the maxillary sinus with unusual glandular formation and lymphoplasmacytic stroma in case 1 and a characteristic solid nest pattern and fibrocellular and hyalinized stroma in case 2. Immunohistochemical studies excluded myoepithelial origin and sinonasal renal cell-like adenocarcinomas. Negativity for p63 and p40 in case 1 ruled out a squamous cell origin. Both cases showed a rearranged EWSR1 gene. Reverse-transcription polymerase chain reaction detected EWSR1-ATF1 fusion gene transcripts, and Sanger sequencing confirmed an EWSR1 exon 11 fused in-frame to ATF exon 3.

Keywords: EWSR1 FISH assay; EWSR1-ATF1; Hyalinizing clear cell carcinoma; Minor salivary gland; Nasal sinus.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged, 80 and over
  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / genetics*
  • Biopsy
  • Carcinoma / chemistry
  • Carcinoma / genetics*
  • Carcinoma / pathology
  • Carcinoma / therapy
  • Endoscopy
  • Exons
  • Gene Fusion*
  • Genetic Predisposition to Disease
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Male
  • Maxillary Sinus Neoplasms / chemistry
  • Maxillary Sinus Neoplasms / genetics*
  • Maxillary Sinus Neoplasms / pathology
  • Maxillary Sinus Neoplasms / therapy
  • Middle Aged
  • Oncogene Proteins, Fusion / genetics*
  • Phenotype
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Stromal Cells / chemistry
  • Stromal Cells / pathology
  • Tomography, X-Ray Computed

Substances

  • Biomarkers, Tumor
  • EWSR1-ATF1 fusion protein, human
  • Oncogene Proteins, Fusion