Human Papillomavirus-Induced Keratinizing Squamous Cell Carcinoma in Ovarian Cystic Teratoma: A Case Report and Literature Review

: Ovarian mature cystic teratoma (MCT), the most common ovarian tumor, undergoes malignant transformation only in a small proportion of cases, most frequently into squamous cell carcinoma. However, malignant transformation into squamous cell carcinoma associated with human papillomavirus (HPV) infection is exceptionally rare. Here, we reported a 43-year-old premenopausal woman who presented with an abdominal mass. CT examination suggested an ovarian MCT, and then the patient underwent surgical resection. Histopathological analysis confirmed a diagnosis of MCT-derived keratinizing squamous cell carcinoma, with HPV types 16 and 59 infections being detected through preoperative cervical cancer screening. According to the 2014 FIGO staging system, the patient was diagnosed as stage IC. The surgery was successful, and adjuvant chemotherapy with the BEP regimen was planned. Notably, malignant transformation of MCT is uncommon, and HPV-related squamous cell carcinoma arising from an ovarian teratoma is scarcely documented. This case highlights the importance of considering malignant transformation in clinical practice, particularly through early assessment based on patient age, tumor size, and tumor marker levels, to ensure timely diagnosis and intervention.