The expression of mammaglobin, S-100, Ki-67, P63 and ETV6 split were detected in twelve cases of acinar cell carcinoma and fourteen cases of mammary analogue secretory carcinoma of salivary gland by immunohistochemistry and fluorescence in situ hybridization respectively.
However, 10 of 17 zymogen granule poor AciCCs showed ETV6 translocation and were reclassified as MASC; the diagnosis of AciCC was retained for cases with intact ETV6.
This translocation was not found in any conventional salivary AciCC (12 cases), nor in other tumor types including pleomorphic adenoma (1 case) and low-grade cribriform cystadenocarcinoma (1 case), whereas ETV6-NTRK3 gene rearrangements were proven in all 3 tested cases of mammary secretory carcinoma.