Sigmoido-ovarian fistula complicating ovarian carcinosarcoma: a case report.

Introduction: Ovarian cancer is the leading cause of death from gynecological cancer. Ovarian carcinosarcomas represent a rare, aggressive entity with a poor prognosis. Spontaneous fistulization of ovarian cancer into the digestive tract is a rare phenomenon. Presentation of case: A 67-year-old woman with a significant history of cardiac rhythm disorders was consulted for abdominal pain. Examination revealed tachycardia and abdominal guarding. Biology pictured elevated inflammatory markers and low prothrombin time. The abdominal computed tomography scan suggested a perforated sigmoid tumor with a peri-colonic abscess and pneumoperitoneum. She was rushed to the operating theater. Upon exploration, it was an ovarian tumor fistulized to sigmoid with peritonitis. She had an en-bloc resection with a terminal stoma. Control radiological study revealed diffuse lymph node metastasis. She was scheduled for chemotherapy. Discussion: This complication worsens the prognosis. The fistulous communication in the digestive lumen leads to the overflow of its microbial deposit. The tumor, therefore, becomes superinfected and may result in pelvic peritonitis in case of secondary rupture. On the other hand, the patient is deprived of the benefit of undergoing neoadjuvant chemotherapy, which will decrease the chances of complete macroscopic cytoreduction. Through a literature review, we aim to shed light on this rare entity in order to clarify its pathophysiological consequences and make adequate therapeutic measures. Conclusion: Fistulization to the large intestine worsens the prognosis of ovarian carcinosarcomas. Surgery is mandatory and should comply with oncological requirements. Adjuvant therapy is mostly needed, although more studies should be conducted to delineate the regimen accurately.