Primary cerebral lymphomatoid granulomatosis: report of four cases and literature review.

BACKGROUND: Lymphomatoid granulomatosis (LYG) is an angiocentric and angiodestructive lymphoreticular proliferation, which usually involves the lungs, but may also involve the central nervous system (CNS). Unique involvement of the CNS has been reported rarely. We report our experience with LYG confined to the brain and review the pertinent literature.

PATIENTS AND METHODS: From January 1995 to September 2007, we identified patients with isolated brain LYG through a search of the histopathology database of the Catholic University of Rome; medical and radiological data were analyzed. Immunophenotype, in situ hybridization analysis of EBV-encoded small RNAs (EBER ISH) and immunoglobulin rearrangement studies were performed on the pathological specimens.

RESULTS: Four patients with brain-LYG (male/female 1:1, mean age 44 years) underwent surgery in the study period. Subsequent therapy was tailored according to LYG grading. At the latest follow-up (range from 18 to 221 months), patient conditions had improved in all cases. EBER ISH was negative in all cases. Study of the IgH chain gene documented a monoclonal pattern in two cases.

CONCLUSIONS: CNS-LYG is a rare disease that should be considered in the differential diagnosis of both diffuse and space-occupying cerebral lesions. Primary cerebral LYG seems not to be associated with EBV and appears to have a better prognosis than systemic LYG with CNS localization, which is frequently EBV positive.