Primary central nervous system lymphoma (PCNSL)
Primary central nervous system lymphoma (PCNSL) is a type of central nervous system restricted non-Hodgkin lymphoma, whose histopathological diagnosis is majorly large B cell lymphoma.
They are extranodal, of the diffuse large B cell type that is confined to the brain, eyes, leptomeninges, or spinal cord, in the absence of systemic lymphoma.
Although PCNSLs generally arise from the parenchyma, lymphomas arising primarily from the dura are termed dural lymphomas (DL). They are typically intraparenchymal. A subset of PCNSLs predominantly arises in the ventricles, with minimal parenchymal involvement.
Most of the lesions are supratentorial and periventricular, often involving deep structures such as corpus callosum and basal ganglion. Isolated intraventricular lymphoma is rare and only a few case reports.
Epidemiology
Primary cerebral lymphoma represents 4%–7% of primary brain tumors, and its incidence has increased in the last 3 decades 1).
History
Bailey first described PCNSL as “perithelial sarcoma” of the CNS and Henry in 1974 recognized its lymphoid origin 2).
Generally, PCNSL of DLBCL type is a highly aggressive tumor and although its prognosis is poor, about one-third of younger patients can hope for cure of the disease 3).
Types
Variants
It typically presents as multifocal T2 hyperintense lesions that both enhance after gadolinium administration and demonstrate mass effect. A case study in 1999 coined the term ‘lymphomatosis cerebri’ to describe an exceedingly rare variant of PCNSL characterised by diffuse parenchymal infiltration of lymphomatous cells.
Diagnosis
Differential diagnosis
Treatment
Outcome
Case series
Randomised trials
Only three completed randomised trials are available for primary CNS lymphoma: one phase 3 and two phase 2 trials 4) 5) 6).