Musculoskeletal coccidioidomycosis: unusual sites of disease in a nonendemic area.

Coccidioidomycosis is a primary pulmonary infection, endemic to the southwestern United States, caused by inhalation of spores in an immunocompetent host. When systemic spread occurs, the dissemination of infection to musculoskeletal sites might account for 20% to 50% of cases. The musculoskeletal manifestations are well recognized by physicians in endemic areas. We report 2 cases encountered in metropolitan Chicago in which morphologically typical, large, yeast-like, encapsulated, endosporulating organisms were identified in tissue samples and Coccidioides immitis was cultured. One patient had a degenerative-type radiographic picture thought to be related to a sports injury. A second patient with skin lesions and a paraspinal mass required emergency decompressive spinal surgery. A history consistent with exposure to Coccidioides organisms was apparent only for the first patient. Although the diagnosis can be established morphologically by identifying the large endospores in tissue samples, the submission of samples for culture and subsequent microbiologic confirmation requires the diagnosis to be considered clinically. This report emphasizes the rarity of the organism in nonendemic areas and the redundant value of using both morphologic and microbiologic modalities.