Pulmonary cryptococcosis with cavitation in an immunocompetent child: a case report and literature review.

BACKGROUND: In recent years, the incidence of pulmonary cryptococcosis (PC) has risen among patients without human immunodeficiency virus (HIV) infection, including individuals with preserved immune function. The clinical manifestations of PC are largely non-specific, frequently presenting with fever, cough, chest tightness, or chest pain. In some cases, PC remains asymptomatic, which increases the likelihood of misdiagnosis or delayed recognition. The present study reports the diagnostic evaluation and therapeutic course of a child with PC and normal immune function, accompanied by a literature review, with the objective of enhancing clinical awareness and reducing disease-related mortality.

CASE PRESENTATION: A 14-year-old girl was admitted to the hospital on April 28, 2025, with cough accompanied by intermittent fever. During the illness, chest tightness and chest pain were reported. Her past medical history was unremarkable. Physical examination demonstrated stable breathing, with scattered rales auscultated bilaterally. Chest computed tomography (CT) revealed extensive inflammatory consolidation with cavitary change in the right upper lobe. Cryptococcus neoformans capsular antigen (CrAg Lateral Flow Assay) was positive in both blood and bronchoalveolar lavage fluid (BALF), whereas cerebrospinal fluid (CSF) testing was negative. Targeted next-generation sequencing (tNGS) of BALF detected Cryptococcus neoformans (7,193 sequence reads), establishing the diagnosis of pulmonary cryptococcosis. Oral fluconazole at 6 mg/kg/day was administered as antifungal therapy. After 6 days of inpatient management, body temperature normalized and clinical symptoms markedly improved. The patient was discharged on day 9 in stable condition. Following discharge, she remained afebrile and free of cough, chest tightness, chest pain, or other complaints. Follow-up chest radiography at 16 weeks demonstrated near-complete resolution of the lesion, and repeat chest CT at 6 months showed absorption of the cavity with clear improvement compared with baseline; fluconazole was subsequently discontinued.

CONCLUSION: PC may develop in children with preserved immune function. In pediatric patients presenting with pulmonary cavitation, non-specific respiratory manifestations, inadequate response to conventional anti-infective therapy, and suspected pulmonary tuberculosis or malignancy, cryptococcus-related etiologic investigations should be performed promptly. Treatment strategies should be individualized according to immune status and disease severity.