Primary squamous cell carcinoma arising from endometriosis of the ovary: A case report and literature review

Cases of squamous cell carcinoma (SCC) arising from ovarian endometriosis have been rarely reported. Most of the patients show a poor prognosis and present with a diminished survival time. We present a SCC case arising from endometriosis, and analyzed the clinical, therapeutic, and pathologic features through a comprehensive literature review. A 43-year premenopausal woman (gravida 2, para 1) presented to our hospital due to sudden pain in lower abdomen. Exploratory laparotomy indicated rupture of left ovarian cyst and intra-abdominal hemorrhage were observed. Frozen section pathologic examination indicated malignant ovarian (left-sided) epithelial tumor (poorly differentiated squamous carcinoma). She received hysterectomy, adnexectomy, and omentectomy. Initially, the patient received 3 cycles of chemotherapy using paclitaxel and cisplatin via peritoneal injection. Subsequently, the regimen was altered to 2 cycles of paclitaxel or cisplatin chemotherapy through intravenous injection due to poor tolerance. Upon diagnosis of vaginal metastasis, 2 cycles of chemotherapy was performed using cisplatin, doxorubicin, and cyclophosphamide. Pathologic analysis revealed massive poorly differentiated squamous carcinoma in the fibrous tissues. Besides, cancer embolus was noticed in the lymphatic vessels. Besides our case, 20 cases of infiltrating SCC of the ovary associated with or arising from endometriosis were found. The tumor was associated with 80% patient mortality in the first few months. Adjuvant chemotherapy with paclitaxel and carboplatin or cisplatin appeared to contribute to the survival duration. The best outcomes were obtained in patients received paclitaxel and carboplatin or cisplatin after radical surgery. In future, further studies are needed to validate the efficiency of such regimen.