Imaging in primary central nervous system lymphoma

Area of Science:

• Neurology
• Oncology
• Radiology

Background:

• Primary central nervous system lymphoma (PCNSL) constitutes about 3% of primary CNS tumors.
• Immunodeficiency is a known risk factor, with rates declining alongside AIDS, yet PCNSL incidence is rising in the elderly immunocompetent population.
• This trend appears independent of diagnostic advancements or broader cancer incidence patterns.

Purpose of the Study:

• To review and present the imaging features of PCNSL.
• To correlate imaging findings with epidemiological data.
• To investigate changes in PCNSL presentation over time.

Main Methods:

• Retrospective review of imaging (CT and MRI) in 38 pathologically confirmed PCNSL cases.
• Analysis of lesion characteristics, including size, shape, multiplicity, and enhancement patterns.
• Inclusion of (1)H-magnetic resonance spectroscopy ((1)H-MRS) data for metabolic profiling.

Main Results:

• PCNSL occurred more frequently in men (58%) than women (42%), with a mean age of 63.
• 120 lesions were identified across 38 patients, with 53% presenting as multifocal tumors.
• Lesions appeared as well-defined masses, hyperdense on unenhanced CT, and showed specific signal intensities on MRI sequences (T2, DWI) and (1)H-MRS (increased Cho/Cr, Cho/NAA, lactate/Cr).
• Lesions are now smaller at diagnosis compared to two decades ago.

Conclusions:

• Imaging findings are consistent with existing literature.
• The study supports the increasing incidence of PCNSL in the elderly immunocompetent population.
• The observed trend towards smaller lesion size at diagnosis warrants further investigation.