Pulmonary alveolar proteinosis.

Three adult patients, two of whom were HIV-seropositive, presented with a dyspnea of two-to-three-day duration associated with dry cough. High-resolution CT scans of the chest revealed a widespread air-space consolidation with "crazy-paving" pattern in all cases, suggesting a pulmonary alveolar proteinosis (PAP). Bronchoalveolar lavage (BAL) retrieved varying amounts of turbid fluid containing abundant, coarsely granular material that stained positively using periodic acid-Schiff (PAS) and PAS with prior diastase digestion. Pneumocystis carinii (PC) cysts were identified in Gomori methenamine silver-stained BAL sediments obtained from the two HIV-positive patients. By electron microscopy, numerous myelin figures were found in the BAL sediments in all cases, confirming a PAP. Histologic examination of lung tissues obtained by open biopsy confirmed a PAP in two cases, with one case showing, in addition, PC cysts.