This is a dramatic presentation of mucinous adenocarcinoma of the colon. There is a large perforation along the anterior aspect of the ascending colon in the area of masslike thickening which extends to the hepatic flexure. There are several small calcifications associated with the colonic mass, which is a common feature of mucinous adenocarcinoma. There is extraluminal stool and gas. These findings alone make a suspicion for perforation in the setting of malignancy very high.

Additionally, there is ileocolic adenopathy. There are multiple areas of nodularity within the mesentery and omentum, consistent with carcinomatosis. This was confirmed at the time of surgery. There is thickening within the distal small bowel which is most likely related reactive inflammation in the setting of perforation (this is confirmed in the pathology report). This patient had a mucinous adenocarcinoma of the colon pathology, which often can present late with advanced disease, and is less likely to perforate as it is more pliable than nonmucinous adenocarcinoma.