Duplication cyst is an extremely rare congenital malformation of the alimentary tract. It occurs most often in the ileum, accounting for over 60% of cases followed by the jejunum and the duodenum (1). The colon is the least common site of enteric duplication. In fact, in a review of 495 alimentary tract duplications only 7% of the duplications involved the colon (2). To our knowledge less than 100 cases have been described in the published literature (3).
Case reportWe present an unusual case of colonic duplication cyst in a 45-yearold Caucasian man who presented to our hospital with lumbar pain. The patient had a medical history of constipation. On admission, the patient was afebrile. Physical examination revealed a large mass in the left upper quadrant with mild diffuse tenderness and no peritoneal signs. Blood laboratory tests were within normal limits. An initial plain X-ray was performed with no abnormal findings. Ultrasonography was insignificant due to gas filled bowels. After the first inconclusive radiological exams, a contrast Barium Enema study was decided to be performed. Barium Enema showed a large air-filled tubular structure in the left upper quadrant containing an air-fluid level (Fig. 1). The same cystic structure was partially filled with contrast due to communication with the transverse colon at the splenic flexure. The shape of the cystic structure changed with peristalsis and the position of the patient oral contrast material was performed. It demonstrated a large airfilled 14 × 7 cm structure containing oral contrast in the left upper quadrant (Fig. 3). CT confirmed the findings of contrast Barium Enema study and a possible diagnosis of colonic duplication of the transverse common was concluded. A surgical intervention was decided in order to prevent complications of the colonic duplication cyst. At operation, the cyst was excised with a segment of (Fig. 2). At the same examination the gastric antrum was recognized as a smaller air-filled structure adjacent to the same tubular structure.