Abstract
A 12-year-old woman was seen at the hospital because of abdominal pain. Laboratory data showed leukocytosis and abdominal plain X-ray film revealed a finding of compression of the intestinal gas. Laparotomy was done under a diagnosis of acute abdomen. A giant cyst, which originated from the connective tissue around the lienal flexura, was twisted clockwise by about 180° surrouding by the great omentum. Complete extirpation of the giant cyst was performed without resection of any adjacent organs. Histologically, the diagnosis of cystic lymphangioma was established. The cyst was composed of numerous leukocytes, erythrocytes and inflammatory exudate.