Atypical presentation of cerebral cryptococcoma in an immunocompetent patient with focal hyperkinetic manifestation: diagnostic challenge in a deep pseudotumoral lesion

Abstract

Case Presentation: A 62-year-old previously healthy woman was admitted with involuntary orofacial movements associated with progressive right-sided weakness for two weeks. On examination, she exhibited orofacial dyskinesia, grade III right hemiparesis, and mild dysarthria. Brain magnetic resonance imaging revealed an expansile lesion in the left basal ganglia, with heterogeneous enhancement and significant perilesional edema, initially suggestive of a primary central nervous system neoplasm. A stereotactic biopsy was performed, and histopathological analysis confirmed cerebral cryptococcoma. HIV serology was negative. Cerebrospinal fluid analysis showed mildly elevated opening pressure, 28 cells/mm³ with lymphocytic predominance, protein level of 92 mg/dL, and glucose of 46 mg/dL (serum glucose 98 mg/dL). Cryptococcal antigen was positive, and culture confirmed Cryptococcus spp. Amphotericin B was initiated. During hospitalization, she developed progressive renal dysfunction attributed to drug-induced nephrotoxicity and electrolyte disturbances. On the tenth day, she presented acute respiratory failure requiring invasive mechanical ventilation, subsequently evolving to cardiorespiratory arrest and later meeting criteria for brain death. Discussion: Cerebral cryptococcoma is a focal granulomatous form of neurocryptococcosis resulting from an organized inflammatory response to fungal invasion of the brain parenchyma. Unlike the classic meningoencephalitic presentation, it may occur in immunocompetent individuals, reflecting a complex interaction between fungal virulence and host immune response. Basal ganglia involvement explains the hyperkinetic phenotype through dysfunction of cortico-striato-thalamo-cortical circuits. Presentation as a deep expansile lesion with marked edema and heterogeneous enhancement closely mimics high-grade neoplasms, delaying diagnostic suspicion. The fatal outcome, despite histological confirmation and treatment initiation, highlights the potential aggressiveness of the disease and current therapeutic limitations. From the perspective of the future of neurology, this case underscores the need to integrate advanced neuroimaging, cerebrospinal fluid biomarkers, and multimodal analytical approaches to enable earlier differentiation between granulomatous infections and neoplastic processes, thereby reducing diagnostic delay and treatment-related complications. Final Comments: Cerebral cryptococcoma should be included in the differential diagnosis of deep expansile lesions, even in immunocompetent patients with unusual motor manifestations. The future of neurology will rely on early diagnostic precision and individualized decision-making to modify outcomes in rare and severe presentations.