Giant ecchordosis physaliphora presenting with progressive neurological deficits: a case report and literature review

Abstract Ecchordosis physaliphora (EP) is a rare benign notochordal remnant. Giant symptomatic cases producing significant neurological compromise are exceptionally uncommon. We report a 46-year-old male presenting with progressive dizziness, dysphagia, and brainstem compression from a 4.6-cm prepontine retroclival EP. MRI demonstrated characteristic T1-hypointense, T2-hyperintense signal with a clival stalk and absent gadolinium enhancement. Surgical decompression via the Kawase transpetrosal approach achieved 60% tumor resection. Histopathology confirmed EP with retained INI-1 (SMARCB1) expression and Ki-67 less than 1%. Giant EP represents a formidable diagnostic and surgical challenge; absent enhancement favors EP over intradural chordoma but does not definitively exclude it.