The patient is known to have perinuclear pattern of antineutrophil cytoplasmic antibodies (p-ANCA) vasculitis. Bronchoscopy revealed extensive blood on both sides. No organisms isolated.

Pulmonary hemorrhage is very uncommon in polyarteritis nodosa (PAN), the lungs are usually spared. Hemorrhage is more often seen in other vasculitides, such as Wegener's or systemic lupus erythematosus (SLE).

In this patient on immunosuppression, the other important differential diagnosis is an opportunistic infection. Bronchoscopy is diagnostic, revealing blood and bronchial washings showing no organisms.