Colonic malignancy mimicking an appendiceal mass.

The records of 99 patients admitted for inflammatory appendiceal mass were evaluated. Eight of these patients (8%) had a malignancy of the right colon with, in four cases, secondary inflammation of the appendix. Remnants of inflammation limited to the appendix were present in 64 patients. These two groups were compared to a group of 21 patients treated in the same period for a palpable malignancy of the right colon. In patients older than 50 years absence of pain, symptoms which last more than one week, a painless palpable mass in the right lower abdomen and the presence of anemia indicate (underlying) colonic malignancy. Barium enema of the colon remains the most reliable method for a correct preoperative diagnosis of colonic malignancy and should be done in every patient older than 50 years who presents with an appendiceal mass, as well as in younger patients with a protracted course of the disease.