Mucocele of the appendiceal stump due to benign mucinous cystadenoma.

Mucocele of the appendix is a rare lesion, characterized by distension of the lumen due to accumulation of mucus material. Correct preoperative diagnosis is seldom achieved. If left untreated, the mucocele may rupture producing a potentially fatal peritoneal spread. The type of surgical treatment is related to the dimensions and histology of the mucocele. In this paper, the case of a 49-year-old woman, with a previous appendectomy, suffering from a painful mass in the right lower quadrant of the abdomen, is reported. Imaging showed a large, cystic structure at the base of the cecum. Surgery revealed a 8x5.5 cm calcified tumor, which was excided together with the appendiceal remnant. Pathological diagnosis was that of a mucocele arising from the appendiceal stump due to the development of a benign mucinous cystadenoma.