October 2004: a 49-year-old man with progressive dementia

Area of Science:

• Neurology
• Oncology
• Neuroimaging

Background:

• A 49-year-old male presented with a 4-month history of progressive cognitive decline, including memory, calculation, and language impairments.
• Associated symptoms included fatigue, weight loss, gait imbalance, and urinary incontinence, suggesting a diffuse neurological process.
• The patient had a history of transfusion-associated Hepatitis C, a potential factor in immune-related conditions.

Observation:

• Neurological examination revealed dysarthria, dysnomia, left-sided neglect, bilateral Babinski signs, and a grasp reflex, indicating bilateral hemispheric dysfunction.
• Electroencephalogram (EEG) showed diffuse slowing and right hemisphere background decrease, suggestive of encephalopathy and a structural lesion.
• Magnetic Resonance Imaging (MRI) demonstrated multifocal FLAIR hyperintensities and patchy enhancement, while Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) revealed focal increased uptake correlating with MRI findings.

Findings:

• Cerebral angiography was unremarkable, ruling out vascular abnormalities as the primary cause.
• Brain biopsy confirmed diffuse infiltrates of malignant cells immunoreactive for CD20, establishing a diagnosis of diffuse large B-cell lymphoma (DLBCL).
• The combination of clinical presentation and neuroimaging findings supported bilateral hemispheric involvement, with DLBCL being the final diagnosis.

Implications:

• This case underscores the importance of considering infiltrating neoplasms, particularly lymphoma, in the differential diagnosis of rapidly progressive dementia.
• Advanced neuroimaging techniques (MRI, FDG-PET) play a critical role in identifying structural and metabolic abnormalities suggestive of CNS lymphoma.
• Morphological and immunohistochemical analysis of brain biopsy remains the gold standard for definitive diagnosis of primary CNS lymphoma, guiding appropriate oncological treatment.