Bilateral ovarian squamous cell carcinoma with an antecedent dermoid cyst in the left ovary.

Ovarian squamous cell carcinoma is a rare malignancy and its occurrence is commonly attributed to malignant transformation of a pre-existing mature cystic teratoma. The de novo occurrence of primary squamous cell carcinoma is extremely rare. Malignant transformation in a mature cystic teratoma is almost always unilateral; however, there have been isolated reports of an uncomplicated mature cystic teratoma in the contralateral ovary. We report here a case of a 40-year-old woman presenting with squamous cell carcinoma of both ovaries with antecedent dermoid cyst in the left ovary, along with involvement of the fallopian tubes, cervix and omentum.