Squamous cell carcinoma arising from ovarian mature cystic teratoma with concurrent cervical high-risk HPV infection and low-grade squamous intraepithelial lesion: a case report

Malignant transformation of ovarian mature cystic teratoma (MCT) is uncommon, with squamous cell carcinoma (SCC) being the predominant type. Its pathogenesis remains poorly understood, and the potential role of human papillomavirus (HPV) infection is controversial. A 58-year-old postmenopausal woman presented with a huge complex cystic-solid pelvic mass. The elevated Serum SCC antigen revealed potential malignant transformation. Intraoperative frozen section revealed squamous cell carcinoma arising from mature cystic teratoma, and comprehensive staging surgery was performed. Histopathological examination confirmed the International Federation of Gynecology and Obstetrics (FIGO) stage IA SCC arising from MCT. The patient achieved complete remission after surgery and four cycles of adjuvant carboplatin/paclitaxel chemotherapy, with no recurrence at 24-month follow-up. Notably, this case was found to have the HPV infection and a low-grade squamous intraepithelial lesion. The cervical lesion was HPV positive with P16 expression, while the ovarian tumor demonstrated HPV negative with P16 negativity and P53 positivity. For patients with ovarian teratoma, it is necessary to be vigilant about the malignant transformation when the patients are elderly with a large mass and elevated tumor biomarkers. However, it is not clear whether the role of the gene mutation-driven mechanism is in the pathogenesis of this case, since substantive evidence based on genomic sequencing is lacking.