An integrated cerebrospinal fluid beta-human chorionic gonadotropin and atrophy-targeted magnetic resonance imaging strategy to reduce diagnostic delays in bilateral basal ganglia germinomas: A case series

Bilateral basal ganglia germinomas are exceptionally rare intracranial germ cell tumors associated with significant diagnostic delays and irreversible neurological impairment. This study addressed this diagnostic challenge by analyzing the largest dedicated cohort of histopathologically confirmed bilateral basal ganglia germinomas (n = 8). We identified alarming diagnostic delays (median, 1.2 years) in 62.5% of cases, culminating in irreversible deficits such as paralysis and cognitive impairment. Key early clinical indicators included adolescent predominance (mean age, 12.4 years), marked male predominance (7:1), cognitive decline (87.5%), and hemiparesis or monoparesis (62.5%). Magnetic resonance imaging detected cerebral atrophy in 87.5% of patients, with 25.0% showing concomitant mass lesions and atrophy, a distinctive radiological pattern not previously emphasized in unilateral basal ganglia germinomas. Cerebrospinal fluid beta-human chorionic gonadotropin analysis demonstrated superior sensitivity to serum testing (57.1% vs 28.6%). To mitigate devastating outcomes, we propose integrated cerebrospinal fluid beta-human chorionic gonadotropin screening combined with magnetic resonance imaging, with an emphasis on atrophy detection. In patients exhibiting progressive deficits or serial radiological progression despite negative biomarker results, stereotactic biopsy should be prioritized to enable early intervention and preserve neurological function.