Contributed by Aaron Berg, MD, and William Pasculle, Sc.D.
The patient is a 64 year old male with a history of lung transplant 4 years previously for chronic obstructive pulmonary disease and silicosis. The allograft lung function was good. The patient developed fevers and cough 4 weeks previous to admission. Upon admission, a chest CT was performed and showed a 9 mm left lingula nodule (Figure 1). Blood cultures, sputum culture, urine Legionella antigen, EBV and CMV viral loads were all negative. Due to suspicion of infection, he was treated with vancomycin and piperacillin/tazobactam, and discharged.
Approximately 15 days later, he again presented to the hospital with persistent low grade fevers, cough, and fatigue. Culture from a bronchoalveolar levage grew Klebsiella, which was treated appropriately. Urine and serum Histoplasmosis antigens were positive as well. For this, he was treated with itraconazole and inhaled amphotericin B. An endobronchial biopsy showed an acute inflammatory infiltrate but a GMS stain was negative for fungal organisms. A CT guided fine needle aspirate was performed on the mass, and showed only inflammatory cells and no organisms. The bronchial wash and CT guided FNA sample were sent for cultures.
Eventually, growth was seen on the sabouraud dextrose plate. Colonies were tan-white, and fluffy (Figure 2). Similar colonies were seen on inhibitory mold agar (IMA) with gentamicin media (Figure 3). Growth was also seen on brain heart infusion agar with gentamicin and chloramphenicol (BHIA) (Figure 4).
Microscopic morphology in the filamentous phase showed septate hyphea with dumb-bell shaped microconidia with no macroconidia.
Fungus sent for confirmatory DNA probe.