[A case of colon cancer resembling submucosal tumor with ossification]

A 62-year-old man was admitted to our hospital because of elevated serum CEA and CA19-9. Colonoscopy disclosed a submucosal tumor (SMT) in the ascending colon. CT showed a tumor with partial calcification, 40 x 30 mm in size. FDG-PET showed no abnormal uptake in the tumor. During a follow-up three months later, colonoscopy showed an ulcer on the upper surface of the SMT, and pathological findings of the biopsy specimen disclosed mucinous adenocarcinoma. Right hemicolectomy was performed. Pathological findings of the resected specimen showed mucinous adenocarcinoma invading the subserosa with heterotopic ossification of the same site as the calcification on CT.