Cryptococcal Meningitis Beyond Immunosuppression: A Case Report in an Immunocompetent Individual.

Abstract

Background: Cryptococcal meningitis is a life-threatening opportunistic fungal infection predominantly seen in immunocompromised hosts, yet it is increasingly recognized in apparently immunocompetent individuals. In tuberculosis-endemic regions, its diagnosis is frequently delayed or missed due to overlapping clinical and cerebrospinal fluid findings with tuberculous meningitis.

Case presentation: A 44-year-old immunocompetent woman presented with a two-month history of progressive diffuse headache and subjective bilateral lower limb weakness. Neurological examination was unremarkable, and initial cerebrospinal fluid analysis revealed marked hypoglycorrhachia (1 mg/dL), elevated protein (356 mg/dL), and lymphocytic pleocytosis. Brain imaging showed leptomeningeal enhancement without mass lesions. Despite negative microbiological testing for tuberculosis, empirical antituberculous therapy was initiated based on presumptive tuberculous meningitis. Pulmonary imaging demonstrated cavitary nodules and calcified lymph nodes. Lack of clinical improvement prompted further investigation; India ink staining and fungal culture of cerebrospinal fluid eventually confirmed Cryptococcus neoformans infection. The patient had no evidence of HIV, diabetes, or other immunosuppressive conditions. Induction therapy with liposomal amphotericin B and fluconazole was administered, followed by consolidation and maintenance fluconazole. She showed marked clinical and cerebrospinal fluid improvement and was discharged on oral fluconazole with sustained recovery.

Discussion: This case illustrates the diagnostic challenge of cryptococcal meningitis in immunocompetent patients, particularly in settings where tuberculous meningitis is common. Early reliance on India ink staining and fungal culture is essential when initial tuberculosis workup is negative or when response to antituberculous therapy is poor. The incidental detection of HHV-6 DNA likely represented viral reactivation without clinical significance.

Conclusion: Cryptococcal meningitis must be considered in immunocompetent patients presenting with chronic meningitis, even in the absence of classic risk factors. Prompt mycological investigation can prevent diagnostic delays and improve outcomes.