We report a case of pulmonary cryptococcosis. An 81-year oldman presented with dyspnea, fever, and an abnormal chest X-ray. Sputum cytology revealed the presence in abundance of oval organisms, 3-15 μm in diameter and palely stained with hematoxylin. C. neoformans was identified by multi-staining with Alcian blue-PAS. The organisms were positive for PAS, and their capsules for Alcian blue. The capsules of the small organisms (<10μm) were not clearly stained (control and Mucicarmine 65%; Alcian blue 62%). On Alcian blue-PAS multi-staining, however, the capsules of 99% of C. neoformans cells were clearly observed and readily distinguished from the coexistent Candida albicans.
Thus, Alcian blue-PAS multi-staining is useful for identifying C. neoformans, and for distinguishing them from other fungi.
