Summary Xp11 translocation renal cell carcinoma (RCC) with SFPQ/PSF-TFE3 gene fusion is a rare epithelial tumor. Of note, the appearance of the gene fusion does not necessarily mean that it is renal ...cell carcinoma. The corresponding mesenchymal neoplasms, including Xp11 neoplasm with melanocytic differentiation, TFE3 rearrangement-associated perivascular epithelioid cell tumor (PEComa) and melanotic Xp11 translocation renal cancer, can also harbor the identical gene fusion. However, the differences between Xp11 translocation RCC and the corresponding mesenchymal neoplasm have only recently been described. Herein, we examined 5 additional cases of SFPQ-TFE3 RCCs using clinicopathological, immunohistochemical, and molecular analyses. One tumor had the typical morphologic features of SFPQ-TFE3 RCC, whereas the other 3 cases demonstrated the unusual morphologic features associated with pseudorosettes formation or clusters of smaller cells, mimicking TFEB RCC. The remaining one showed branching tubules and papillary structure composed of clear and eosinophilic tumor cells. Immunohisochemically, all 5 cases demonstrated moderate (2+) or strong (3+) positive staining for TFE3, PAX-8 and CD10, whereas no cases demonstrated TFEB, Cathepsin K, CA-IX, CK7, Melan-A, or HMB-45 expression. Genetically, the fusion transcripts were identified in 3 cases by reverse transcription polymerase chain reaction (RT-PCR). On the basis of fluorescence in situ hybridization (FISH) analysis, all the cases were detected SFPQ-TFE3 gene fusion. Clinical follow-up data were available for all the patients and no one developed tumor recurrence, progression, or metastasis. We also review the differences between SFPQ-TFE3 RCC and the corresponding mesenchymal neoplasm despite the identical gene fusion. The presence of pseudorosettes also expands the known histological features of SFPQ-TFE3 RCC.
Summary Mammary analogue secretory carcinoma (MASC) of salivary glands is a newly recognized tumor entity. To explore a more practical and convenient immunohistochemical approach to distinguish MASC ...from other tumors arising from salivary glands as well as to expand the immunologic and genetic lineage of MASC, we examined 17 MASC using clinicopathologic, immunohistochemical and molecular analysis. 18 cases of acinic cell carcinoma (AciCC), 18 cases of adenoid cystic carcinoma (ACC), 22 cases of mucoepidermoid carcinoma (MEC), and 14 cases of basal cell adenocarcinoma (BCA) were brought in for comparison. 17 MASC not only shared similar architectures with intraluminal or intracellular secretion but also low-grade vesicular nuclei. In addition, they were all immunoreactive for S-100 and SOX-10, while only 3 of 17 demonstrated reactivity for GATA-3, P63, and 4 of 17 were focally positive for CD117. ETV6 translocation was detected in 10 cases by fluorescence in situ hybridization (FISH), whereas intact ETV6 was noted in 2 cases. Our data proposed a combined immunohistochemical panel to distinguish MASC from other tumors arising from salivary glands and expanded the immunologic and genetic lineage of MASC.
