Gallium-67-citrate and bone scintigraphy in disseminated North American blastomycosis

We present a patient with North American blastomycosis involving lung and bone. Chest radiographs and CT scan showed a mass in the lung. Bone scintigraphy detected a photon-deficient area in the sternum and 67Ga SPECT showed uptake in the right upper lung and in the sternum. A diagnostic thoracotomy and needle biopsy from the sternal lesion revealed granulomatous infection due to Blastomyces dermatitidis. After 3 mo of antifungal therapy, the follow-up 67Ga study showed no evidence of the original lesions but demonstrated a new, asymptomatic, unsuspected lesion in the left infraspinatous muscle. This case illustrates that North American blastomycosis should be included in the differential diagnosis in cases of atypical pulmonary disease with bone involvement, even in geographic regions that are not considered endemic for this microorganism. Gallium-67 and bone scintigraphy may be useful in determining the extent of dissemination, in detecting occult lesions and in the follow-up of response to therapy.