2023 Volume 43 Issue 7 Pages 1085-1087
The patient was an 80-year-old man who was referred to our hospital with suspected intra-abdominal abscess after a visit to a previous hospital for lower abdominal pain. Abdominal CT (computed tomography) showed a 70 x 80 mm low-density area on the right side of the pelvis that was in contact with the end of the ileum, and we decided to perform drainage via a transanal ileocolostomy. The drainage tube was placed under colonoscopic guidance, but the drainage fluid from the fistula was jelly-like, clear, and colorless; upon review of the CT images, we found that the low-density area, which we had thought was suggestive of an intra-abdominal abscess, was, in fact, contiguous with the appendiceal tip; based on this new finding, we considered the diagnosis of an ileocolic fistula formed by penetration of an appendiceal mucinous tumor. We opted for surgical treatment, and performed ileal resection of the affected segment. The histopathological diagnosis was ileal perforation by a low-grade appendiceal mucinous tumor. Initially, we thought that the hypodense area on the right side of the pelvis was an intra-abdominal abscess, but the nature of the draining fluid and review of the CT images led us to revise the diagnosis to an appendiceal mucinous tumor. In addition, drainage treatment of the appendiceal mucinous tumor proved ineffective, and we considered surgical resection as being preferable from an oncological standpoint.
