Communicating hydrocephalus after resection of a meningioma ventral to the foramen magnum

Tumors in or near the foramen magnum may cause communicating or non-communicating hydrocephalus (HC), depending on their size and location. Here, an 81-year-old female developed communicating HC following the resection of a meningioma ventral to the foramen magnum. An 81-year-old female presented with numbness in the left neck and left hemiparesis. The magnetic resonance revealed an 18-mm tumor ventral to the foramen magnum that significantly enlarged over the past 6 months. She underwent total tumor resection but then presented with progressive HC both clinically (i.e., instability of gait with confusion) and radiographically (computed tomography). Following placement of a lumboperitoneal (LP) shunt, symptoms markedly improved. Further, the cerebrospinal fluid (CSF) analysis showed elevated cell counts and protein concentrations, indicating likely “leakage” of intratumoral contents postoperatively contributing to the progressive HC. Patients presenting with acute meningiomas ventral to the foramen magnum may develop postoperative communicating HC attributed to tumor-related CSF leakage of necrotic intratumoral components that can be successfully treated with a LP shunt.