Multiple Pulmonary Nodules in an Immunocompetent Indigenous Male

Case Report: A previously well indigenous male ranger in his early 30s from a rural community in tropical Australia was admitted to hospital with a 2‐week history of pleuritic chest pain, fevers, chills and cough. Several days prior to symptom development he had been involved in leaf blowing at the ranger camp, with many dead eucalyptus trees in the surrounding area. Physical examination was unremarkable. CXR and CT chest revealed numerous (>50) bilateral lung nodules ranging in size from a few millimetres to several centimetres in diameter. HIV, HTLV‐1 and melioid serology and vasculitic screen were negative. A CT‐guided core biopsy of a lung nodule confirmed Cryptococcus gattii (C. gatti). MRI brain was normal, as was the CSF, with negative CSF cryptococcal antigen. He received IV Amphotericin and oral Flucytosine for 6 weeks followed by oral Fluconazole (expected to be continued for at least 12 months), with resolution of symptoms. Repeat CT chest 3 months post treatment commencement showed significant reduction in the size and number of pulmonary lesions.

Discussion: Innoculation of C. gatti is usually via inhalation and pulmonary involvement is the most common presentation. Haematogenous spread can then occur to the central nervous system, and less commonly to other sites. Cryptococcosis is more common in the immunocompromised but can also occur in immunocompetent individuals. In Australia, C. gatti has been particularly associated with eucalyptus trees and cryptococcus disproportionately affects Aboriginal people. The 3 main chest radiographic patterns in immunocompetent patients include solitary or mulitple lung masses (usually large), air space consolidation or reticulonodular interstitial changes. C. gattii is considerably more likely than C. neoformans to lead to large masses (cryptococcomas) in the lungs and/or brain. Radiological presentation with numerous lung nodules such as in the aforementioned patient is rare. Treatment involves antifungal therpay and consideration of surgical resection in selected patients.