Pleural effusion in an immunocompetent host with cryptococcal pneumonia: A case report.

BACKGROUND: Pulmonary cryptococcosis is an opportunistic infection that mainly occurs among immunocompromised patients although it can sometimes occur in immunocompetent individuals. However, the imaging findings of pulmonary cryptococcosis in immunocompetent hosts differ from those in immunosuppressed patients. In addition, the most common imaging findings of isolated pulmonary cryptococcosis are single or multiple nodules. Cavities and the halo sign are, however, prevalent in immunosuppressed patients. In immunocompetent patients, lung consolidation, pleural effusion or cavities are scarce.

CASE SUMMARY: A 29-year-old Asian male was admitted to our hospital with complaints of cough and fever that had persisted for a month. As a chest computed tomography scan showed consolidation in his left lower lobe, he was initially diagnosed with pneumonia and received antibiotic treatment. A second review of the chest computed tomography image revealed multiple cavities and pleural effusion. Flexible fiberoptic bronchoscopy was subsequently performed, bronchoalveolar lavage fluid and serum cryptococcal antigen tests were positive. Cryptococcus capsules were observed in bronchoalveolar lavage fluid ink stain. Histopathological examination of a percutaneous lung biopsy from the left lower lobe further revealed granulomatous inflammation, and periodic acid-Schiff staining showed red-colored yeast walls, signifying pulmonary cryptococcosis. The patient was then treated with a daily dose of fluconazole (0.4 g), but the cough and fever still persisted. We therefore changed treatment to voriconazole (0.2 g, twice a day), and the patient's clinical outcome was satisfactory.

CONCLUSION: Although rare, clinicians should not disregard the possibility of cavities and pleural effusion occurring in immunocompetent hosts without underlying diseases.