Primary central nervous system lymphoma (PCNSL)

Primary central nervous system lymphoma (PCNSL) is an aggressive and rare subtype of non Hodgkin lymphoma, arising exclusively in the CNS with a poor prognosis.

They are extranodal, of the diffuse large B cell type that are 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⁾.

see Primary central nervous system lymphoma epidemiology.

see Primary central nervous system lymphoma in AIDS

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

Primary central nervous system lymphoma classification.

Variants

see Lymphomatosis cerebri.

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

see Primary central nervous system lymphoma diagnosis.

Differential diagnosis

Primary central nervous system lymphoma differential diagnosis.

Treatment

see Primary central nervous system lymphoma treatment.

Outcome

Primary central nervous system lymphoma outcome.

Case series

see Primary central nervous system lymphoma 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)}.

Case reports

Primary central nervous system lymphoma case reports.