Cecal Mass, Ameboma

Abstract

Listen

Translate article

Introduction: The differential diagnosis of a cecal mass includes inflammatory, infections and neoplastic etiologies. In the U.S., we often fail to consider infectious causes in a patient who presents with CT evidence of a cecal mass and lymphoadenopathy. The aim of this case report is to present such a patient with an ameboma. Case: A 50-year-old Ecuadorian Male was seen for evaluation of findings on CT of the abdomen. The CT showed diffuse wall thickening of the cecum. The patient denied diarrhea, nausea, vomiting, or fever. Appetite was good and his weight was stable. He had daily formed stools denied BRBPR. His ROS was non contributory. He was not taking any medications. Physical Exam: was unremarkable.Work up included: CBC, BMP, LFT, O/P, all normal. Colonoscopy was normal until the cecum which had an ulcerated, friable on contact mass encompassing one third of the lumen of the cecum; a normal appearing Ileum; multiple biopsy were taken of the mass. The patient was started on metronidazole 500 mgs PO TID, while waiting for biopsies result. Biopsy of cecum mucosa revealed: acute and chronic inflammation and rare branched glands and organisms consistent with E. histolytica. Giemsa stain highlighted the organisms. Discussion: Intestinal amebiasis is caused by the protozoan E. histolytica. Most of Entamoeba infections are asymptomatic as in our patient but this depends on a multiplicity of factors. Clinically the infection will have a variety of symptoms that can range from mild diarrhea to severe dysentery, abdominal pain, bloody stools. Rarely patients with longstanding infection can develop a hyperplastic granulomatous lesion which can form a mass resembling colon cancer, and can present both with a palpable tender mass and as a mass seen on CT or on colonoscopy. These so called amebomas such as in our patient are usually solitary lesions, of variable size, affecting men between 20 and 60 years of age. These lesions most commonly develop in the cecum as in our patient. If biopsy proves that E. histolytica is present, then the duration of treatment with metronidazole should be 7 to 10 days to completely eliminate the intestinal infection. Summary: In patients who present for evaluation with a colonic mass, especially those that are localized in the cecum our main concern should be to rule out a malignancy, but when evaluating this patients we should take in consideration the epidemiology and prevalence of diseases, as in our case presentation, where the patient was living in a highly endemic area for Entamoeba. Once stool and multiple biopsies of the lesion have been accomplished patients should be started on a metronidazole, while waiting for biopsy results.