Intracranial pseudolymphoma.

Intracranial pseudolymphoma is a rare tumor of the central nervous system. A 35-year-old woman presented with a frontal subcutaneous tumor. Magnetic resonance imaging revealed a left frontal meningeal tumor involving subcutaneous tissue without bone involvement. The mass was completely removed and the histological aspect of all tumor sections was that of a lymphoid hyperplasia with polyclonal proliferation. These findings were characteristic of pseudolymphoma defined as a hyperplasia of follicular and diffuse lymphoid type with assessment of its polyclonality by immunophenotyping on frozen sections, completed by molecular biology techniques.