Malacoplakia of the skin: overview of a rare clinical entity

Malacoplakia is a rare acquired, infection-related granulomatous disorder, that may affect many systems, but typically occurs in the urinary tract. Cutaneous involvement is less prevalent, and most commonly presents with a perianal or genital region localization. Cutaneous malacoplakia is believed to be caused by an acquired bactericidal defect of macrophages in the setting of chronic infections and immunocompromised states. A diagnosis of cutaneous malacoplakia should be considered when encountering non-specific granulomatous lesions that are refractory to treatment. Histologic findings are marked by the presence of foamy macrophages containing the pathognomonic Michaelis-Gutman bodies.

The aim of this review is to discuss the current perspectives on the pathophysiology, clinical features, diagnosis, and treatment of this disease. We would also like to emphasize that the integration of clinical information, microscopic findings, and exclusion of other cutaneous granulomatous processes is necessary to accurately diagnose this exceedingly rare disease and provide opportunity for therapeutic intervention.

Data for this work were collected from the published literature and textbooks.

Combined surgical excision and protracted antibiotic courses appear to have the highest success rate. Antibiotics should be culture specific, but drugs that easily permeate the macrophages appear to be the best choice.