CNS Non-Hodgkin's Lymphoma With Atypical T2 Hyperintensity and Necrosis Mimicking Glioblastoma Multiforme: A Radiological Enigma.

A 45-year-old female presented with a 15-day history of headache and blurred vision. MRI of the brain revealed multiple irregular, T2-hyperintense lesions with significant surrounding edema, central necrosis, peripheral rim enhancement, and corpus callosum involvement resulting in a "butterfly" appearance. These imaging features led to an initial radiological impression of multifocal glioblastoma multiforme. Subsequent histopathological examination of a brain biopsy provided a definitive diagnosis of CNS non-Hodgkin's lymphoma (CNS-NHL). The biopsy showed dense perivascular cuffing by atypical large lymphocytes with notable mitoses and adjacent edema. This report illustrates an imaging presentation of CNS lymphoma that differed from common patterns, particularly the prominent T2 hyperintensity within the enhancing rim and central necrosis, posing a diagnostic challenge resolved using histopathological analysis. The findings emphasize the importance of tissue diagnosis in cases with complex neuroimaging presentations suggestive of high-grade glioma.