A Rare Case of Malakoplakia Presenting as a Polypoid Lesion

Abstract

Purpose: Malakoplakia, a rare form of chronic granulomatous disease, typically involves the genitourinary tract and is defined by its characteristic histopathological findings. It is usually associated with an immunocompromised state or with a concurrent chronic infection. The second most common location is the gastrointestinal tract and most colonic cases have been diagnosed with a concurrent adenocarcinoma. We report a case of a 64 y/o healthy African American male who was referred to our clinic for a screening colonoscopy. Four nodular appearing polyps, all less than 5 mm in size were found and excised using standard biopsy forceps. Histological examination of three of the four polyps was consistent with tubular adenomas. The fourth polyp, located in the ascending colon, had focal aggregates of granular histiocytes with targetoid Michaelis-Gutmann bodies consistent with Malakoplakia. This is a distinct case because it was diagnosed on endoscopic samples of typical appearing polypoid lesions, as prior described reports were found in surgical specimens. In addition, there was no evidence to suggest an immunocompromised state or infection. Furthermore, with the association regarding adenocarcinoma, a screening protocol may be warranted in these types of patients.Figure: No Caption available.