Multiloculated mesothelial cyst presenting as a malignant mimic.

A 46-year-old woman was referred for a second opinion regarding an intra-abdominal mass discovered on imaging performed for abdominal pain and distension. The tumour appeared to involve the small bowel, left colon and mesentery and was initially thought to be consistent with an infiltrative tumour or loculated mucinous ascites. Due to the unusual appearance of the tumour and suspicion for an omental-based mass, a laparoscopic resection was recommended to the patient. Intraoperatively, the tumour was found to be a multiloculated, benign appearing, omental cyst without involvement of the bowel and was completely resected laparoscopically. Pathology demonstrated a multiloculated peritoneal mesothelial cyst.