Sequencing of Sclerosing Microcystic Adenocarcinoma Identifies Mutational Burden and Somatic Variants Associated With Tumorigenesis

BACKGROUND/AIM: Sclerosing microcystic adenocarcinoma (SMA) is a rare oral cavity neoplasia, histologically resembling microcystic adnexal carcinoma (MAC) of the skin. Only nine SMA cases have been reported in the literature, frequently in the context of immunosuppression; SMA has not been recognized in the most recent WHO tumor classification. We sought to identify potential molecular mechanisms of tumorigenesis in a case of SMA relative to those known for MAC. CASE REPORT: A 41-year-old female with psoriatic arthritis undergoing immunosuppression therapy presented with a tongue mass. Biopsy revealed a diagnosis of SMA. Partial glossectomy and neck dissection showed no residual tumor or nodal disease. RESULTS: whole exome sequencing revealed moderate mutational burden and putative loss of function mutations in CDK11B but no overlap with known MAC mutations. CONCLUSION: We characterized the genomic profile of SMA for the first time, identifying both mutational burden and unique somatic variants associated with tumorigenesis.