Cytologic diagnosis of Cryptococcus neoformans in HIV-positive patients.

Abstract

To present experience with the cytologic diagnosis of pulmonary cryptococcosis in bronchial washings and bronchoalveolar lavage in human immunodeficiency virus (HIV)-positive patients in Thailand. The study group consisted of 54 HIV-positive patients admitted to the Faculty of Medicine, Srinagarind Hospital, during the period January 1992-June 1994. Bronchial washing and bronchoalveolar lavage specimens were studied for Cryptococcus neoformans by routine Papanicolaou and special staining methods. The Cryptococcus organism, an encapsulated yeast with a clear halo on Papanicolaou-stained smears, was found both extracellularly and in histiocytes in 4 of 54 (7.4%) cases. A definitive diagnosis was confirmed by positive staining of the capsular mucopolysaccharides with periodic acid-Schiff and Mayer's mucicarmine stain and of the cell wall with methenamine silver. Lung biopsy was performed in one case and revealed cryptococcosis. This study underscores the usefulness of cytologic screening in the detection of this opportunistic pulmonary infection. The cytopathologist and cytotechnologist should be alert for the presence of Cryptococcus in cytologic specimens from HIV-positive patients.