Primary leptomeningeal central nervous system lymphoma in an immunocompetent adolescent: an unusual presentation.

We report a case of primary leptomeningeal central nervous system (CNS) lymphoma with atypical imaging features in an immunocompetent adolescent who presented with diplopia, seizures, vomiting and subsequent unresponsiveness. Primary leptomeningeal CNS lymphoma is rare in the pediatric population, and this is one of few reported cases in the literature of large B-cell lymphoma isolated to the leptomeninges in a teenager.