Superficial siderosis in long-standing pilocytic astrocytoma.

Background: Pilocytic astrocytoma (PA) rarely spreads along neuraxis, and association with superficial siderosis (SS) and chronic signs of intracranial hypertension is exceptional.

Case Report: A 48-year-old woman presented with slow onset hearing loss in the past year. Clinical examination revealed dysarthria, positive Romberg test, and severe optic neuropathy. Cerebrospinal fluid (CSF) analysis showed numerous red blood cells, increased proteins and LDH, and high opening pressure. Brain and spine MRI demonstrated extensive superficial siderosis, bone remodeling of the skull base and spine, and diffuse nodular leptomeningeal enhancement. Histological examination of a nodule in the dorsal spine evidenced PA.

Conclusion: We report a case of PA associated with dural remodeling and SS. The mechanism of SS is unclear but might be related to meningeal tumor infiltration and altered CSF composition and resorption.