330 Low-Grade Mucinous Neoplasm of the Appendix in the Setting of a CDKN2A Gene Mutation: A Potential Association Risk Factor

The molecular pathways that contribute to the development of appendiceal mucinous neoplasms have recently received additional attention. The most common identified mutations found in low-grade appendiceal mucinous neoplasm (LAMN) are in the KRAS and GNAS genes, which often are concomitantly mutated. KRAS and GNAS mutations coexist with some frequency in other entities, including pancreatic intraepithelial neoplasia (PanIN) and villous adenomas of the colorectum. Similarly, genetic alterations in the tumor suppressor gene cyclin dependent kinase inhibitor 2A (CDKN2A) have been implicated in PanIN progression and in colonic adenomas. CDKN2A gene mutation previously has been associated with hereditary forms of cutaneous melanoma, colorectal carcinoma, pancreatic adenocarcinoma, gastric carcinoma, epithelial ovarian carcinoma, prostate carcinoma, head and neck squamous cell carcinoma, and non-small cell lung carcinoma. The presence of CDKN2A mutation in precursor lesions in the colon and pancreas suggests there may be an association to LAMN, similar to the GNAS mutation association with LAMN, PanIN, and villous adenoma of the colon. To date, there are no descriptions of this potential association in the literature, and additional studies are needed. We present a case of an incidental LAMN in a 37-year-old patient with a strong family history of malignancy and a germline CDKN2A mutation who underwent a prophylactic subtotal colectomy for polyposis.