Squamous cell carcinoma of the ovary

A 45-year-old woman developed a grade III and stage III squamous cell carcinoma of the left ovary 12 years after a hysterectomy for treatment of endometriosis. Origin from a teratoma or a Brenner tumor was excluded. Despite extensive surgery with additional radiation therapy and chemotherapy, the patient died five months after the malignancy was diagnosed. Squamous cell carcinoma of the ovary, either de novo or arising from endometriosis, has rarely been reported. We describe a case of ovarian squamous cell carcinoma in which endometriosis is strongly favored as the origin, but that remains speculative.