Abstract
PURPOSE: To present a rare case of pulmonary cryptococcosis that exhibited radiological findings consistent with interstitial pneumonia in a patient diagnosed with IgA (Immunoglobulin A) nephropathy. PATIENTS AND METHODS: A 66-year-old man was admitted to the hospital with interstitial lung disease. The cryptococcal capsular antigen test was positive in both serum and bronchoalveolar lavage fluid. Histopathological examination of the bronchoscopically obtained lung biopsy and positive culture results revealed the presence of Cryptococcus yeast, while no Cryptococcus species were detected in the cerebrospinal fluid. Collectively, these findings confirmed the diagnosis of pulmonary cryptococcosis. RESULTS: The fluconazole dosage was tailored according to the patient's renal function, and the lesions in the right lung were significantly improved following one month of antifungal therapy. CONCLUSION: This case illustrates that in immunocompromised patients, pulmonary cryptococcosis may manifest with imaging findings resembling interstitial pneumonia. Therefore, clinicians should consider pulmonary cryptococcosis in the differential diagnosis of interstitial pneumonia, particularly in immunocompromised individuals.