Papers of the Week

Mature teratoma is a common benign ovarian germ cell tumor, accounting for about 20% of ovarian tumors. The malignant transformation of this tumor is less than 2%. The most common type is squamous cell carcinoma, followed by adenocarcinoma. Malignant transformation of colonic mature teratoma is extremely rare. We here report a case of malignant transformation of primary mature teratoma of the colon. The type of malignant transformation was adenocarcinoma.