Presentation
Abdominal pain
Patient Data
Within the right iliac fossa, there is a well-defined discretely marginated mass of uniform signal intensity. The density is slightly higher than fluid but lower than signal density of surrounding soft tissue. This structure measures 4.7 x 10.3 cm in size. There is some faint mural high-density consistent with patchy calcification of the wall. There also two small gas locules within. This lesion is blind ended and in close proximity to the cecal pole. There is slight soft tissue irregularity of the cecal pole at the level of appendiceal orifice.
There is mild inflammatory infiltration of the soft tissues surrounding this structure. Pelvic free fluid noted.
Case Discussion
The differential diagnoses for this lesion include appendiceal mucocele (simple mucocele vs, cystadenoma/cystadenocarcinoma) or much less likely given the size acute appendicitis.
In differentiating between cystadenoma (benign) and cystadenocarcinoma (malignant), soft tissue thickening, wall irregularity and the presence of Pseudomyxoma Peritonei have been found to be the most specific markers for malignancy 1.
The patient went on to have a resection. Pathology revealed appendiceal cystadenoma.