Fluorescence in situ hybridization analysis on cytologic smears: An accurate and efficient method in the diagnosis of melanotic Xp11 translocation renal cancer
© 2018 Wiley Periodicals, Inc. Melanotic Xp11 translocation renal cancer is a rare category of MiTF/TFE3 neoplasms morphologically resembling Xp11 translocation renal cell carcinoma, Xp11 translocation perivascular epithelioid cell tumor, and melanoma. The diagnosis requires demonstration of TFE3 gene rearrangement, by either fluorescence in situ hybridization (FISH) at the Xp11.2 locus or by TFE3 immunohistochemistry. As cytology smears can be useful adjuncts in cytogenetic and molecular testing, we demonstrate TFE3 rearrangement by FISH analysis on cytologic smears in melanotic Xp11 translocation renal cancer. An 18-year-old girl presented with a large right renal mass. Intraoperative scrape smears were performed on suspicious aortocaval lymph nodes. A subset of smears was stained (Papanicolaou and DiffQuik). Morphologically, the neoplastic cells exhibited abundant clear vacuolated cytoplasm and moderate to marked nuclear pleomorphism. Unstained and destained smears were examined for TFE3 rearrangement by FISH. Positive TFE3 FISH results on formalin-fixed paraffin-embedded tissue correlated with the positive FISH findings of TFE3 gene rearrangement on cytologic smears. Therefore, the diagnosis of melanotic Xp11 translocation renal cancer was rendered. In Xp11 translocation associated neoplasms, FISH analysis on cytologic smears can be an efficient, accurate, and cost-effective method for evaluating TFE3 rearrangement.
Gupta A, Micale M, Bernacki KD. Fluorescence in situ hybridization analysis on cytologic smears: An accurate and efficient method in the diagnosis of melanotic Xp11 translocation renal cancer. Diagn Cytopathol. 2018 Sep;46(9):786-789. doi: 10.1002/dc.23961. Epub 2018 May 3. PMID: 29722173.