A rare case of malignant transformation: squamous cell carcinoma arising on the basis of an ovarian mature cystic teratoma.

Background: Ovarian mature cystic teratomas (MCTs) are the most prevalent benign ovarian tumors, with rare potential for malignant transformation, most commonly into squamous cell carcinoma. Accurate diagnosis is crucial for optimal management and prognosis.

Methods: A 27-year-old woman presented with a year-long history of intermittent abdominal and groin pain. Imaging studies, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), revealed a mixed solid-cystic lesion in the left adnexal region, consistent with an MCT exhibiting radiologic signs of malignancy. The patient underwent unilateral salpingo-oophorectomy, and intraoperative frozen section analysis suggested a mature cystic teratoma. However, definitive histopathological examination confirmed squamous cell carcinoma arising from the MCT. This case highlights the limitations of frozen section analysis in detecting malignancy.

Conclusions: Malignant transformation of MCTs, though rare, poses significant diagnostic and therapeutic challenges. Comprehensive preoperative imaging and meticulous postoperative histopathological evaluation are essential for accurate diagnosis and effective management. This case underscores the importance of interdisciplinary collaboration in addressing complex gynecologic pathologies.