An Updated Case Report of a Long‐Term Survivor With Stage <scp>IVB</scp> Ovarian Squamous Cell Carcinoma Arising From Mature Cystic Teratoma

A 68-year-old woman visited a gynecological clinic complaining of abdominal distension and pain. A large immobile tumor was palpable in the upper left abdominal area. Computed tomography showed an ovarian tumor measuring 20 cm in diameter anterior to the left kidney. A barium enema revealed that the descending colon was narrow, with a wall that was irregularly transformed by the tumor. Cytoreductive debulking surgery was performed. A histological examination demonstrated squamous cell carcinoma arising from a mature cystic teratoma of the ovary. The descending colon was invaded by cancer cells up to the mucosal tissue, and four lymph nodes were metastatic. After surgery, she received eight cycles of adjuvant chemotherapy. After the last treatment, she has been free of the disease for longer than 18 years. We describe the clinical characteristics of this case and speculate on the reason for the long-term survival.