Squamous cell carcinoma arising within a mature cystic teratoma of the ovary in a postmenopausal woman: A case report and literature review.

Malignant transformation of mature cystic teratomas (MCTs) of the ovary is rare, with squamous cell carcinoma (SCC) being the most common histologic subtype. Due to its nonspecific clinical presentation and similarity to benign dermoid cysts, preoperative diagnosis is often challenging, resulting in delayed recognition and poorer outcomes. Risk factors such as postmenopausal status, large tumour size, and elevated tumour markers should serve as red flags prompting clinical suspicion for malignant transformation within an ovarian teratoma. This report describes the case of a 52-year-old woman who presented with chronic abdominal distension, bloating, and early satiety. Imaging revealed large bilateral mature cystic teratomas with associated right-sided hydroureteronephrosis and an elevated CA-125 level. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy, omentectomy, appendectomy and peritoneal washings. Histopathology confirmed a moderately differentiated squamous cell carcinoma arising within a mature cystic teratoma, confined to the right ovary (pT1a). Squamous cell carcinoma arising in a mature cystic teratoma represents a rare but clinically significant form of malignant transformation. This case underscores the importance of considering malignancy in postmenopausal women with large or symptomatic ovarian dermoid cysts and highlights the role of comprehensive histopathological evaluation in establishing an accurate diagnosis and guiding optimal management.