[1303] Mammary Analogue Secretory Carcinoma: Expansion of a Clinicopathologic Profile and Identification of New Sources for Recategorization

Christopher C Griffith, Simion Chiosea, Raja R Seethala. UPMC, Pittsburgh, PA

Background: Mammary analogue secretory carcinoma (MASC) of salivary glands is a recently described tumor, histologically and biologically similar to secretory carcinoma of breast (ETV6-NRTK3 translocated). It is assumed that most were historically classified as acinic cell carcinoma (AciCC) but other 'reservoirs' may exist. In order to expand and refine the clinicopathologic profile of this rare tumor, we combine prospectively diagnosed MASC with a retrospective cohort derived from an array of diagnostic categories.
Design: MASC were prospectively diagnosed over a 10 month period. Also, 297 archived salivary gland tumors, spanning several diagnostic categories, were reviewed by histomorphology and immunophenotype. Cases with pink vacuolated cytoplasm, luminal mucin, and/or strong S100 positivity were evaluated for ETV6 translocation by FISH (n=67). Clinicopathologic parameters on confirmed cases were recorded.

Reservoirs of MASC
Original diagnosisNumber reviewedNumber reclassified as MASC
Adenocarcinoma, NOS2414
Mucoepidermoid carcinoma1651
Signet ring cell carcinoma51
Polymorphous low grade adenocarcinoma40
Sinonasal non-ITAC*40
*non-ITAC = non-intestinal type adenocarcinoma

Results: A total of 36 MASC were confirmed (9 prospective and 27 retrospective). Sources of retrospectively identified MASC are summarized in the table. 30 cases were drawn from our consult files. Tumor sites were 26 parotid, 3 submandibular, 3 soft palate, 1 buccal mucosa, 1 upper lip and 1 base of tongue. MASC occurred in a wide age range (10-75 years, average 45.6) and had a male predominance (21 male:14 female). 15 tumors were uninodular/cystic, 13 infiltrative and 4 multinodular/cystic. 18 tumors showed predominantly cribriform architecture, 9 solid, 5 intracystic and 4 papillary. 19 showed at least rare papillae and 22 at least some intracystic growth. Perineural and angiolymphatic invasion was common, 36.7% and 20% respectively. All tested cases were S100 positive (n=25) but half showed variable to focal staining. p63 showed peripheral staining in 5/22 cases, thus highlighting intraductal components. 5 cases were clinically aggressive - 4 nodal metastasis and 1 disease related death following recurrence and metastasis.
Conclusions: A wide array of diagnostic categories should be surveyed to more accurately characterize MASC, since in addition to AciCC, adenocarcinoma, NOS is a common source of MASC. MASC demonstrate a variety of morphologic features and range from low to high grade. Papillary and intracystic growth are fairly common. A subset of tumors behave aggressively.
Category: Head & Neck

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 203, Monday Morning


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