Synonyms:
a.k.a. CNS lymphoma
Diagnosis:
Suggested by MRI and confirmed by pathology (brain biopsy/resection)
Findings on Investigations:
CT:
- PCNSL: hyperdense on CT
- Secondary lymphoma; hyperdense on noncontrast and enhances after contrast.
- Variable in AIDS.
MRI:
- Single or multiple lesions. Usually supratentorial, affecting the deep grey matter nuclei and Periventricular. Subependmal spread. Occur at grey-white matter junction. May encase the ventricle. May involve: corpus callosum, septum pellucidum, or encase the ventricles
- Involves basal ganglia, ependymal spread, corpus callosum
- T1 +contrast: dense enhancement, ring enhancing lesions, ependymal enhancement. Dural enhancement usually occurs in secondary lymphoma
- T1: hypointense or isointense
- FLAIR: hypointense or homogenous, rarely it’s hyperintense
- DWI: hyperintense but not as bright as a stroke, ADC: hypointense
MR Perfusion: increased perfusion. Differentiates it from toxoplasmosis.
Thallium scan: increased. Differentiates it from toxoplasmosis.
Pathology:
Histology:
- Pleomorphic, Small round blue cells without cytoplasmic processes. Perivascular lymphocytes. Necrosis may occur.
Immunohistochemistry: CD20 B cell marker.
– Primary CNS lymphoma is associated with AIDS with EBV. Mainly a B cell lymphoma.
Treatment:
Omya reservoir:
- Intraventricular methtrexate
Radiation therapy
Steroids
Radiation therapy
Steroids