Acute diverticulitis of the terminal end of the ileum, which clinically simulated acute appendicitis, developed in a man. At operation, the inflamed mass was indistinguishable from neoplasm. Several ileal diverticula were demonstrated by a series of gastrointestinal x-ray films made seven weeks prior to the onset of acute abdominal symptoms. Since acute diverticulitis of this part of the ileum is quite unusual and unexpected, this diagnosis rarely comes to mind, and it was not considered in this case.
Bartone NF, Grieco RV. Acute Diverticulitis of the Terminal Ileum. JAMA. 1967;202(12):1103–1105. doi:10.1001/jama.1967.03130250085022