A rare presentation and recurrence of a retroperitoneal Müllerian cyst in a male patient: A case report

Abstract Introduction The retroperitoneal Mullerian cysts are extremely rare lesions seen mostly in female patients but their occurrence in males is quite possible. Their exact etiology stills unknown, its histological and immunohistochemical characteristics may serve as an evidence that reflects its origin. Case presentation We present a case of a resected retroperitoneal Mullerian cyst that reoccurred severely after 3 months after the first laparotomy in a male patient with a significant history of testicular teratocarcinoma. Due to of the cyst’s localization and its proximity to vital retroperitoneal structures, total surgical resection couldn’t be made and the recurrence was minimized by post-operative oral chemotherapy. Discussion The retroperitoneal Mullerian cyst is a benign cystadenoma that could be confused with other retroperitoneal lesions, which makes the pathological examination with the immunohistochemical study of the cyst’s wall essential to make the diagnosis. The immunopositivity to Cytokeratin 7 and the immunonegativity to Cytokeratin 20 is a key feature that confirm the diagnosis whenever the retroperitoneal Mullerian cyst is suspected. Due to its high vascularity, we highly recommend the administration of chemotherapy which targets the proliferative cyst’s cells. Conclusion The RMCs are rare benign lesions that tend to reoccur if total surgical resection isn’t made, when the total resection couldn’t be achieved the unspecific anti-mitotic drugs may help to minimize the recurrence and improve the life quality of the patient.