Erdheim-Chester disease mimicking an intracranial trigeminal schwannoma: case report.

Erdheim-Chester disease (ECD) is non-Langerhans histiocytosis that can affect multiple organ systems. It usually affects middle-aged patients, and only a few reports of ECD in children appear in the literature. Central nervous system involvement is a common feature that usually occurs as infiltration of the hypothalamus-pituitary axis, cerebellum, and/or brainstem. Meningeal involvement occurs less commonly. In this article, the authors discuss a rare pediatric case of ECD presenting as an infiltrative mass of the trigeminal nerve and resembling the clinical and imaging features of a trigeminal schwannoma.