FDG-PET/CT for Effective Staging of Disseminated Blastomycosis

We present the case of a 67-year-old man undergoing immunosuppressive therapy with known pulmonary blastomycosis who presented with knee swelling and fever. FDG-PET/CT performed to exclude septic arthritis revealed increased uptake within the right epididymis and multiple osteoarticular, cutaneous, and subcutaneous sites. Cultures obtained from bronchoalveolar lavage, urine, right knee arthrocentesis, and subcutaneous tissue all demonstrated Blastomyces dermatitidis , compatible with disseminated blastomycosis (DB). To the best of our knowledge, this is the first case of DB in a human subject documented by FDG-PET. This case showcases FDG-PET as a potentially sensitive imaging modality in staging blastomycosis multiorgan involvement, aiding in identifying culture sites by revealing clinically and radiologically unsuspected foci of infection.