Serous adenocarcinoma arising from endometriosis in cesarean section abdominal wall scar: a case report and literature review

Background: Abdominal wall endometriosis has been well-described and can occur after caesarean section. However, malignant transformation of abdominal wall endometriosis is rare, less than 40 cases have been reported so far and its pathogenesis is still poorly understood. Case report: Here, we report a 48-year-old woman, gravida 1, para 1, with a history of uneventful caesarean delivery presented with increasing pain and a rapid growing mass in her cesarean section scar. Serum tumor markers, especially CA125 and CA199 increased remarkably. Physical examination and pelvic magnetic resonance imaging showed a mass sized 15 cm in maximum diameter and the enlarged pelvic lymph nodes. Neoadjuvant chemotherapy and surgery were performed, followed by chemotherapy. The surgery contained radical resection, excision of bilateral accessory, hysterectomy, omentectomy, lymph node excision and abdominal dermoplasty. Histopathological examination showed a serous adenocarcinoma of endometrial origin with lymph node metastasis. Recurrence was noted 3 months after surgery and the patient was followed up until now. 33 literatures on similar cases were reviewed. Conclusion: Extensive lymph nodes metastasis might predict a poor prognosis in case of malignant transformation of abdominal wall endometriosis. Radical resection followed by chemotherapy is the most common treatment. Once recurrence occurs, treatments including chemotherapy and radiotherapy are usually ineffective.