We describe the case of a heavy marijuana and tobacco smoker who
presented with progressive exertional dyspnea of 2 months’ duration,
and bilateral nodular lung infiltrates. Examination of the lung fields
was normal, and lung function tests showed mild airflow obstruction
with moderately reduced gas transfer. BAL returned green-black fluid
consisting predominantly of macrophages laden with carbon pigment.
Thoracoscopic lung biopsy showed miliary necrotizing granulomata with
an alveolar exudate of carbon-laden macrophages within macroscopically
blackened lung. The differential diagnosis of pulmonary granulomata in
this patient is discussed.