[Study on pulmonary cryptococcosis disclosed by chest radiographic screening in Nagasaki Prefecture]

We conducted a retrospective investigation of 20 cases of pulmonary cryptococcosis discovered by chest radiographic screening in Nagasaki Prefecture among 2,011,577 persons over a period of 9 years, Apr. 1989-Mar. 1998. Eight males and 12 females between 15 and 72 years of age(mean: 46.6 years) were diagnosed as having pulmonary cryptococcosis. The mean detectability of pulmonary cryptococcosis by screening was 0.99 per 10(5) persons: 1.30 for residents, 0.51 for school children and 0.80 for workers. Chest radiography showed shadows of solitary nodules in 9 patients, multiple nodules in 4, infiltration in 4 and others in 3. Cavities were noted in 7. However, it was difficult to distinguish between pulmonary cryptococcosis from pulmonary tuberculosis and pulmonary cancer based on radiographic data alone. Final diagnoses for 11 and 3 patients, respectively, were made using TBLB or BAL, and lung biopsy. Sixteen patients each underwent an Eiken-Latex agglutination test (serum cryptococcus antigen test) and 15 (93.8%) had positive results. The serum antigen level thus appears to be a useful indicator in the supplementary serological diagnosis of pulmonary cryptococcosis.