JMA Journal

Figure 1. a) Contrast-enhanced horizontal CT image: The appendix is in contact with a large cyst (arrowhead). The continuity between the appendix and cyst is unclear on CT.
b) Contrast-enhanced sagittal CT image: The IVC is significantly compressed by the large cyst (arrowhead).
CT: computed tomography; IVC: inferior vena cava.

Figure 2. Intraoperative findings.
a) The large cyst originated from the sigmoid mesentery.
b) Post-enucleation image of the abdominal cavity showing that only the cyst was removed without damage to the ureter or other parts of the colon.

Figure 3. Resected specimen.
a) The cyst measured 210 160 mm and was covered by a relatively thick fibrous capsule. The cystic fluid was old bloody.
b) Histological image of the cyst wall showing the cystic lumen covered with fibrin, blood, and degenerative material. No epithelial or endothelial cells were present. The cyst wall was composed of fibrous connective tissue with numerous neutrophilic infiltrates.