He then named the macrophages von Hansemann cells and the inclusions Michaelis-Gutmann bodies. Malacoplakia is a rare disorder that occurs most commonly in the immunocompromised patient. Cutaneous involvement is infrequent and typically perianal. The morphological features are varied and may appear as skin-colored, yellow, or pink abscesses or violaceous papules or nodules. Lesions often are ulcerated or may form sinus tracts that drain.
Pathogenesis is unknown, although faulty bacterial killing by macrophages is suspected.
The diagnosis is made by histopathologic studies that show an infiltrate of numerous Hansemann macrophages that contain Michaelis-Gutmann bodies. The natural history is usually benign, although a chronic protracted course can be expected. Escherichia coli has been cultured from some of the reported cutaneous lesions, 1-3 and, as is the case with our patient, treatment with ciprofloxacin and other antibiotics can be successful. 1 Excision may be attempted in very localized disease. Since the diagnosis of malacoplakia can only be made by biopsy, we stress the importance of performing a biopsy for culture as well as histopathologic examination on any atypical abscesslike lesion, nodule, or plaque appearing in an immunocompromised patient.