Computed Tomography Detection of Schistosomal Appendicitis

Schistosomiasis is the second most prevalent parasitic disease worldwide, which is rarely reported in developed countries like Hong Kong. We report a case of schistosomal appendicitis in a 79-year-old male presenting with right lower abdominal pain. Computed tomography of the abdomen and pelvis showed dilated appendix with adjacent stranding, suggestive of acute appendicitis. Long-segment circumferential interrupted mural calcification was also seen along the large bowel and appendix, together with capsular calcification extending towards the centre of liver with turtleback appearance, highly suspicious of prior schistosomiasis infection. Subsequent histological study of the appendicectomy specimen revealed transmural suppurative inflammation of the appendix with numerous calcified Schistosoma ova in the appendiceal wall, compatible with schistosomal appendicitis. Having discussed the incidence and pathogenesis of schistosomal appendicitis, we stress the importance of considering prior schistosomal infestation as a cause of acute appendicitis, especially in patients who have emigrated or are travelling from endemic areas.