[A case of secondary pulmonary cryptococcosis showing various radiographic changes during its natural course without antifungal treatment].

A 58-year-old man who had been prescribed corticosteroids for rheumatoid arthritis in another hospital was admitted to our hospital for examination of an abnormal chest shadow. We obtained a positive result for cryptococcal antigen in the serum, in a measurement done as a screening test for abnormal chest shadows. We diagnosed secondary pulmonary cryptococcosis through a transbronchial biopsy. He showed various radiographic changes, including multiple nodular shadows, cavities and partial resolution during the natural course without antifungal treatment. This case taught us that secondary pulmonary cryptococcosis causes a more varied range of radiographic changes than its primary form, that measurement of cryptococcal antigen in serum is useful as a screening test of pulmonary cryptococcosis, and that it is important to consider whether a particular patient should be treated or not.