Concurrent Identification of Novel EGFR–SEPT14 Fusion and ETV6–RET Fusion in Secretory Carcinoma of the Salivary Gland

Abstract

Salivary gland secretory carcinoma, also termed mammary analogue secretory carcinoma (MASC), is a recently described salivary gland neoplasm with characteristic histomorphologic findings similar to those of secretory carcinoma of the breast and harboring recurrent ETV6–NTRK3 fusions. Recent findings have expanded the molecular profile of salivary gland secretory carcinoma to include multiple novel ETV6 fusion partners, including RET, MET, and MAML3. Here, we report a case of cystic MASC with cribriform and papillary histology harboring two gene fusions, ETV6–RET and EGFR–SEPT14, identified by targeted RNA sequencing. The presence of the rearrangements was confirmed by FISH, RT-PCR, and Sanger sequencing. This is the first EGFR–SEPT14 fusion reported in secretory carcinoma as a single event or in association with an ETV6 rearrangement. This finding adds to the expanding molecular profile of this tumor entity, and may translate into novel treatment strategies.