[1257] Mammary Analogue Secretory Carcinoma of Salivary Glands, Containing the ETV6-NTRK3 Fusion Gene. Hitherto Undescribed Salivary Gland Tumor Entity

A Skalova, T Vanecek, R Sima, J Laco, I Weinreb, RHW Simpson, F Passador-Santos, A Ryska, IV Leivo, Z Kinkor, M Michal. Charles University, Faculty of Medicine, Plzen, Czech Republic; Charles University, Faculty of Medicine and University Hospital, Hradec Kralove, Czech Republic; University Health Network, Toronto, Canada; Royal Devon and Exeter Hospital, Exeter, United Kingdom; Haartman Institute, University of Helsinki, Helsinki, Finland; Private Bioptic Laboratory, Plzen, Czech Republic

Background: We present a series of thirteen salivary gland tumors with histomorphological and immunohistochemical features reminiscent of secretory carcinoma (SC) of the breast. This is a hitherto undescribed and distinctive salivary gland neoplasm, with features of both salivary acinic cell carcinoma (AciCC) and mammary SC.
Design: The patients comprised 8 men and 5 women, with a mean age of 48 years (range 26-59). Eleven cases occurred in the parotid gland, and one each in the minor salivary glands of buccal mucosa and palate. The mean size of the tumors was 2.3 cm (range 0.9 to 5.5 cm). Duration of symptoms was recorded in 9 cases and ranged from 2 months to 30 years. Clinical follow-up was available in 11 cases, and ranged from three to ten years. Three patients suffered local recurrences. Two patients died, one of them due to multiple local recurrences with extension to the temporal bone, and another one due to metastatic dissemination to cervical lymph nodes, pleura, pericardium and lungs.
Results: Microscopically, the tumors have a lobulated growth pattern and are composed of microcystic and glandular spaces with abundant eosinophilic homogenous or bubbly secretory material positive for PAS, mucicarmine, MUC1 and MUC4. They also show strong vimentin and S-100 protein positivity. For this tumor we propose a designation mammary analogue secretory carcinoma of salivary glands (MASC). We have demonstrated a t(12;15) (p13;q25) ETV6-NTRK3 translocation in all but one cases of MASC. This translocation was not found in any conventional salivary AciCC, whereas ETV6-NTRK3 gene rearrangements were proven in all three cases of mammary secretory carcinoma.
Conclusions: Our results strongly support the concept that MASC and AciCC of salivary glands are different entities and should be recorded separately in salivary gland tumor classifications.
Category: Head & Neck

Tuesday, March 23, 2010 9:00 AM

Platform Session: Section G, Tuesday Morning

 

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