Cryptococcus neoformans infection presenting as a mediastinal mass in an immunocompetent child with parrot exposure: a case report and literature review

Abstract

Cryptococcus neoformans typically causes pulmonary or central nervous system (CNS) infections, but mediastinal mass as its primary manifestation is rare—especially in immunocompetent children with pet parrot exposure. This study reports a 7-year-old girl who presented with recurrent fever and a mediastinal mass secondary to Cryptococcus neoformans infection, with a 5-month history of daily contact with parrot feces. Conventional diagnostic tests (e.g., fungal culture, serology) were negative, and the diagnosis was confirmed by targeted metagenomic next-generation sequencing (tNGS) of bronchoalveolar lavage fluid (BALF). The patient received a three-phase antifungal regimen: induction with amphotericin B + flucytosine, consolidation with fluconazole, and maintenance with low-dose fluconazole. After one year of treatment, the mediastinal mass nearly resolved, and no recurrence was observed. A literature review, supplemented with specific cases of parrot-associated Cryptococcus neoformans infection, highlights that parrot exposure is an underrecognized risk factor for pediatric cryptococcosis, and tNGS significantly improves diagnostic efficiency for atypical extrapulmonary manifestations. This case emphasizes the importance of inquiring about pet bird exposure in children with unexplained mediastinal masses and fever, and supports the use of tNGS for early, non-invasive diagnosis.