Cryptococcosis mimicking lung cancer in an immunocompetent patient: A case report.

Cryptococcosis predominantly affects immunocompromised individuals, but cases have been reported in immunocompetent hosts. Pulmonary involvement often presents nonspecific features that could resemble lung malignancy. We present a case of a 49-year-old immunocompetent, HIV-negative, non-smoker man with progressive respiratory symptoms and significant weight loss. Imaging revealed multiple pulmonary nodules with mild metabolic activity. Non-invasive diagnostic studies were inconclusive. Histopathological examination of lung tissue demonstrated encapsulated yeasts consistent with Cryptococcus spp., confirmed by fungal culture and MALDI-TOF mass spectrometry. Later, cerebrospinal fluid analysis also showed encapsulated yeasts. The patient was treated successfully with fluconazole, achieving complete clinical and mycological remission.