A Mesenteric Pseudocyst of the Mesocolon

Abstract

A 64-year-old man with a chief complaint of abdominal pain was evaluated by his physician in April 2016. A CT scan showed a 12-cm lesion with low density in the abdomen. Colon perforation with abscess formation was diagnosed, and the patient was transported to our hospital. Contrast CT showed a well-demarcated lobular lesion without contrast enhancement, and some type of tumor was suspected. Abdominal ultrasound and MRI suggested a cystic lesion, but no definitive diagnosis could be reached. The patient remained symptomatic, and surgery was performed because a malignancy could not be ruled out.
Laparotomy showed an elastic soft lesion in the right upper abdomen, a right hemicolectomy was performed, and the lesion was completely resected. Macroscopic examination showed a 12-cm cystic lesion filled with a yellow serous fluid. Histopathology showed a cyst wall comprised of fibrous connective tissue with inflammatory cells, but without epithelial cells. A mesenteric pseudocyst was diagnosed. Mesenteric pseudocysts are rare in adults. This case is reported, and the relevant literature is reviewed.