[Post-renal transplant pulmonary cryptococcosis, which was difficult to differentiate from a pulmonary tumor].

A 61-year-old man, with a history of renal transplant for immunoglobulin A (IgA) nephropathy and surgery for advanced gastric carcinoma, was noted to have a nodular shadow of 1.3 cm in diameter in the left lung( S8) based on chest computed tomography( CT), and was suspected to have primary pulmonary carcinoma or a metastatic pulmonary tumor, for which surgical resection was performed. A rapid pathological diagnosis of inflammatory granuloma was made, and the patient was finally diagnosed as having pulmonary cryptococcosis based on the histopathology, and received fluconazole postoperatively. Patients with organ transplant history showing a nodular shadow in the lung should undergo a careful workup in consideration of both malignant tumor and infection.