A 29-year-old man with hospital-acquired cavitary pneumonia.

Cavitary lung processes pose a formidable diagnostic challenge. Causes vary widely and include cavitary pneumonia, vasculitis and malignancy. In some cases, patient history and basic work-up may yield a diagnosis, but in others, an extensive work-up, including tissue biopsy, may be necessary to establish the cause. The authors present a case of cavitary pneumonia that complicated an open lung biopsy. It developed in the hospital and was caused by mucormycosis, a potential emerging infection causing health care-associated infections.