A case report of colonic Ameboma mimicking colon cancer in an immunocompromised patient.

INTRODUCTION AND

IMPORTANCE

Entamoeba histolytica is an anaerobic protozoan. It infects humans causing Amoebiasis. Most infections are asymptomatic; however, clinical manifestations include intestinal or extraintestinal. In rare instances, patients can present with Ameboma: a mass of granulation tissue consisting of a core of inflammation with peripheral fibrosis related to chronic amoebic infection usually found in the cecum/ascending colon.

PRESENTATION OF CASE: A 50-year-old patient presented with signs and symptoms of bowel obstruction. He had raised inflammatory markers and was HIV positive on treatment and virally suppressed. At laparotomy a hepatic flexure stricture with desmoid reaction, and wall thickening with induration at the mesenteric border of mid-transverse colon was found, with disseminated nodular disease. Histology confirmed entamoeba histolytica infection.

DISCUSSION: The parasite exists in two forms: a cyst stage and a trophozoite stage: the form causing invasive disease. The presentation of intestinal amoebiasis ranges from an asymptomatic carrier state, colitis, to abscess formation and bowel perforation The management principles: to eliminate the invading trophozoites and eradicate the organism's intestinal carriage and manage complications such as obstruction, fulminant colitis, or toxic megacolon with surgery.

CONCLUSION

This case identifies a rare cause of bowel obstruction in a patient without a travel history. Even with the lack of significant risk factors other than HIV, clinicians should be aware of the infective causes of colonic mass/stricture outside of malignant causes. Entamoeba histolytica is an infection of impoverished communities in developing countries, it should remain high on our differential for tumour-like granulation tissue in the colon.