A Case of Retroperitoneal Leiomyosarcoma Presenting as a Cystic Lesion

Abstract

A 76-year-old woman had been found in 2010 to have a 3-cm cystic lesion in the retroperitoneum on a computed tomography (CT) scan performed as part of regular monitoring of an abdominal aortic aneurysm. She presented at a local clinic with upper abdominal pain, and abdominal contrast-enhanced CT showed a cystic mass of maximum diameter 13 cm in the retroperitoneum caudad to the transverse duodenum, with a large amount of internal hematomas. A retroperitoneal cystic mass with intracystic hemorrhage was diagnosed, and the patient was referred to our hospital for further investigation and treatment. In light of the possibility of malignancy, retroperitoneal tumorectomy was carried out. The resected specimen was a cystic tumor of maximum diameter 13 cm that was filled with a fluid component. Histopathological testing resulted in the diagnosis of retroperitoneal leiomyosarcoma with internal hemorrhage. The patient's postoperative course was uneventful, and she was discharged on Day 10 of hospitalization. Primary retroperitoneal leiomyosarcoma is rare, and most reported cases have been solid tumors. This case of a patient with a retroperitoneal leiomyosarcoma that presented as a cystic lesion is reported along with a brief discussion of the literature.