Difficulty in the Cytodiagnosis of Mammary Analogue Secretory Carcinoma: Survey of 109 Cytologists with a Case Originating from a Minor Salivary Gland.

BACKGROUND: Mammary analogue secretory carcinoma (MASC) of the salivary gland shows morphologic similarities and shares an immunophenotype and characteristic ETV6-NTRK3 translocation with secretory carcinoma of the breast. We present a buccal case of MASC along with a survey-based debate about its cytologic diagnosis by fine-needle aspiration (FNA).

CASE: FNA of the buccal nodule of a 58-year-old Japanese man was initially performed by 3 cytologists who gave different assessments of the Papanicolaou classification (i.e., class II, III, and V). To investigate the potential for discrepant diagnosis of MASC on a larger scale, we distributed a survey with questions about the cytological diagnosis of the present case to cytologists at other institutions. A total of 109 cytologists completed the survey, providing varying assessments of the Papanicolaou classification: class I/II (14%), class III (53%), and class IV/V (33%). Most of the respondents (72%) could not identify a particular tumor or disease. Even the respondents who identified a particular tumor suggested widely differing diagnoses, from a benign lesion to various malignant tumors. Only 2 respondents correctly identified MASC.

CONCLUSION: Our experience and the results of the survey suggest difficulty in the cytodiagnosis of MASC.