Abstract
Cystic lymphangiomas of the mesocolon are very rare in adults. They are usually asymptomatic, but can present with an acute abdomen. We report an adult patient with cystic lymphangioma of the mesocolon that manifested with peritonitis. A 33-year-old man presented with fever and severe pain with muscle guarding in the left abdomen. Laboratory data indicated high-grade inflammation. Enhanced computed tomography (CT) showed multiple low-density masses with peripherally enhancing rims, strongly suspicious for cysts, in the left abdomen. Based on a diagnosis of peritonitis, emergency surgery was performed and revealed many cysts in the descending mesocolon. Histopathological examination findings indicated a cystic lymphangioma. The post-operative course was uneventful, and 1-year follow-up CT showed no recurrence. This case demonstrates that cystic lymphangiomas of the mesocolon in adults can present with acute peritonitis, although this is extremely rare. Complete resection is required for accurate diagnosis and for preventing recurrence.