Decoding MRI Presentation of Primary Central Nervous System Diffuse Large B Cell Lymphoma: A Novel Subgroup...

Area of Science:

• Neuroradiology
• Oncology
• Medical Imaging

Background:

• Primary central nervous system diffuse large B-cell lymphoma (PCNSL) in immunocompetent patients presents aggressive behavior and challenging imaging characteristics.
• Accurate radiological characterization is crucial for diagnosis and prognosis.

Purpose of the Study:

• To update conventional MRI features of PCNSL in immunocompetent patients.
• To identify distinct radiological subtypes of PCNSL using unsupervised clustering.
• To explore early survival differences among the identified radiological subgroups.

Main Methods:

• Retrospective evaluation of 100 immunocompetent patients with histopathologically confirmed PCNSL.
• Analysis of pre-biopsy 1.5T or 3.0T brain MRI including T1, T2, FLAIR, DWI, and post-contrast T1 sequences.
• Unsupervised hierarchical clustering to define radiological subgroups and Cox regression for survival analysis.

Main Results:

• Four radiological subgroups were identified: classical mass-forming (40%), CSF surface-predominant (22%), infiltrative (20%), and atypical mass-forming (18%).
• Lesion characteristics varied significantly, including multifocality, supratentorial involvement, T2 signal intensity, and enhancement patterns.
• Exploratory survival analyses showed significant differences (p=0.02) across subgroups, with higher mortality in CSF surface-predominant and infiltrative patterns.

Conclusions:

• This study provides an updated MRI characterization of PCNSL in immunocompetent patients.
• Four distinct radiological subgroups were identified, offering a foundation for future molecular correlations.
• These radiological subtypes may aid in prognostic stratification for PCNSL patients.