Clinical diagnostic problems associated with cecal ameboma: case report and review of the literature.

Amebiasis is uncommon in developed countries. Its clinical presentation can be variable and non-specific, and the diagnosis can be easily overlooked. Among the wide variety of clinicopathologic manifestations of the intestinal amebiasis, amebomas occur rarely, resulting from the formation of annular colonic granulation tissue, usually in the cecum or ascending colon. This report describes the case of a 65-year-old female who presented with a painful mass in the right hypochondrium and intermittent abdominal cramping, associated with defecation difficulty. Radiologic examination depicted thickening of the cecal wall and its ring-like stenosis in association with a mesenteric reaction. Because of concentric thickening of the cecal wall and the mass-like appearance, a preliminary clinical diagnosis of cecal cancer was made, and the patient was referred to the Clinic for surgical treatment. Histologic examination of the surgical specimen after segmental colectomy confirmed the diagnosis of cecal ameboma. The authors conclude that multiple granulomas of amebic trophozoites can be better recognized after PAS staining, and that the pathognomonic feature of protozoa-ingested red blood cells was also seen in the surgical specimen.