Ovarian Squamous Cell Carcinoma Arising from Mature Cystic Teratoma: A Case Report

Mature cystic teratoma of the ovary (MCTO) is the most common ovarian germ cell tumor. Its malignant transformation is a rare complication that occurs in almost 2% of the MCTs. MCTO is benign and usually appears between 30 and 40 years of age, but patients with malignant ovarian MCT are 10–15 years older than those with benign MCT. The most common malignant transformation in MCTO is Squamous Cell Carcinoma (SCC) which is rarely diagnosed with pre-operative imaging.We report the case of a postmenopausal woman, presenting with severe abdominal pain and a large palpable mass in her abdomen. She was diagnosed postoperatively with SCC arising from MCTO which was confirmed histopathologically. The patient received postoperative chemotherapy and was well at 6-month follow-up after chemotherapy.MCTO is benign, but can rarely become malignant in older ages. So MCTO-arising SCC should be considered in elderly women with abdominal pain and mass, and also some other evident features such as large tumor diameter, elevated serum markers, and solid components in Magnetic resonance imaging (MRI).