Tumoral presentation of primary central nervous system lymphomatoid granulomatosis.

Purpose: Lymphomatoid granulomatosis (LYG) is an angiocentric Epstein-Barr virus (EBV) related B-cell proliferation associated with a reactive T-cell component with an uncertain malignant potential. LYG present at diagnosis as a mass lesion in the central nervous system (CNS) is rare, and only a few cases have been reported. In this article we present four cases of tumoral CNS-LYG and propose some guidelines for its management.

Methods: Clinical, pathological, imaging and laboratory information of four immunocompetent patients, all of them treated surgically, with a final diagnosis of LYG and presenting with an isolated intracranial tumoral mass is reviewed.

Results: Two parenchymal lesions were located in the cerebellum and temporal lobe, and the other two involved the cavernous sinus. At surgery they were avascular, hard, lard-like, necrotic and plastic well-defined lesions, with invasion of the leptomeninges and thrombosis of the small leptomeningeal arteries and veins. Intraoperative pathology excluded any tumor. Pathological studies showed a polymorphic and polyclonal infiltration around, in the wall and into the lumen of medium-sized cortical and leptomeningeal vessels causing their obstruction and tissular necrosis. EBV-infected cells were present.

Conclusions: Making a preoperative diagnosis of CNS-LYG appearing initially as a tumoral mass is difficult because of the lack of pathognomonic clinical symptoms or imaging signs. Surgical management with radical resection of the mass is almost always followed by the long-term local control of the lesion, although the disease may have a disseminated, systemic or malignant evolution.