Abstract
A 71-year-old woman who had been observed for an asymptomatic abdominal mass for ten years visited our hospital because of a one-month history of abdominal distention. Abdominal CT scan showed a 22×15 cm multilocular cystic tumor in the left abdomen and a left hydronephrosis. The tumor had a tendency to increase, and so we performed an operation with a diagnosis of a retroperitoneal cystic tumor. The infant's head sized tumor was located in the retroperitoneal space from dorsal side of the mesosigmoid to the left diaphragm, and it was totally resected. There was brown turbid fluid retention within the tumor and the wall of the tumor showed a necrotic change. Pathological findings showed no malignant cells and the diagnosis was a retroperitoneal cystic tumor with xanthogranulomatous change. Follow-up studies for half a year have shown no evidence of recurrence.
