Lymphomatosis cerebri: diagnostic challenges and review of the literature.

Lymphomatosis cerebri (LC) is a rare variant of a primary central nervous system non-Hodgkin's lymphoma (PCNSL) characterised by diffuse infiltration of tumour cells throughout the brain parenchyma. We present a 68-year-old immunocompetent woman with headaches, dizziness, blurred vision, localised right leg weakness and rapidly progressive dementia. A brain MRI demonstrated diffuse T2 hyperintense white matter lesions that did not enhance with contrast. The clinical differential diagnosis of these lesions included metastatic disease, infectious or inflammatory process such as sarcoidosis, lymphoma, demyelinating disease and less likely vascular aetiology, such as vasculitis or ischaemic stroke. A right frontal stereotactic brain biopsy was non-diagnostic. The patient eventually died from aspiration pneumonia following a pneumonectomy for a primary lung adenocarcinoma. The diagnosis of LC was established on postmortem examination of the brain. 2016 BMJ Publishing Group Ltd.