Malakoplakia of Bone: A Case Report and Review of the Literature

A sixty-one-year-old woman presented with right knee pain. Imaging demonstrated osteonecrosis, pathologic fracture, and a permeative lesion. A biopsy with irrigation and debridement was performed. Cultures grew Escherichia coli, and histology showed features of malakoplakia, a rare lesion of uncertain etiology usually found in the genitourinary tract. The patient was treated successfully with antibiotics.

Malakoplakia, although rare, should be included in the differential diagnosis of permeative bone lesions, especially in an immunocompromised patient.