Cutaneous malakoplakia.

Malakoplakia is an acquired granulomatous disorder first described by Michaelis and Gutmann in 1902. The pathogenesis of malakoplakia is poorly understood, but it is thought to be secondary to an acquired bacteriocidal defect in macrophages occurring mostly in immunosuppressed patients or in the setting of autoimmune disease. Malakoplakia has been described in numerous anatomic locations, most commonly in the genitourinary tract. Microscopically, malakoplakia consists predominantly of sheets of macrophages known as von Hansemann cells with scattered targetoid intracytoplasmic inclusions known as Michaelis-Gutmann bodies. Cutaneous malakoplakia is a rare entity with less than 50 cases reported in the literature. In this article, we review cutaneous malakoplakia including the clinical, gross, and microscopic features as well as the treatment and prognosis of 40 cases of cutaneous malakoplakia identified in the literature.