Extranodal malignant lymphomas may arise in the CNS in the absence of lymphoma outside the nervous system at the time of diagnosis. it is different from secondary involovement of the nervous system in systemic lymphomas.
Primary CNS lymphomas ( PCNL) were first described by Bailey in 1929 as "perithelial sarcoma."
Primary CNS lymphoma constitutes about 3% of all brain tumors.
Most are large B-cell lymphomas , only 2% of T-cell origin.
PCNL affects all ages, with a peak incidence in immunocompetent subjects during the sixth and seventh decade of life.
In immunocompromised patients, the age at manifestation is lowest in individuals who have an inherited immunodeficiency ( 10 years ) , followed by transplant recipients ( 37 years ) and AIDS patients ( 39 years ).
Common location is the brain parenchyma surrounding the ventricular system, but any craniospinal structure can be involved. AIDS epidemic led to increase in the incidence of Lymphoma. The clinical manifestations are similar to other intracranial space occupying lesions of the brain and like other brain tumors CT scan and MRI with contrast and MR spectroscopy helps to diagnose these tumors.
Majority of patients present with focal neurological deficit. Some patients present with features of raised intracranial pressure like headache and vomiting. Few patients present with neuropsychiatric symptoms and seizures. Eye symptoms due to uveitis or vitreous lymphoma may occur in about 5 percent cases. Dementia may also be a symptom of cns lymphoma.
About 50% of transplantation associated primary cns lymphomas appear within a year after transplantation.
PCNSL occur as a single or multiple masses in in deep location in cerebral hemisphere or in the peri ventricular region. It may be diffuse or well demarcated. Diffuse infiltrative form may present as lymphomatous cerebri. Meningeal lymphoma may present as meningioma or meningitis.
On CT scan it is infiltrative lesion with indistinct margins and isodense or hyperdense with homogeneous enhancement with minimal surrounding edema or compressive effect. Solitary lesion in majority of cases. Lesions are usually supratentorial and localized in the deep periventricular areas.
Clinical presentation is similar to any other space occupying lesion. Steroid , cerebral decongestants and antiepileptic medication are given and a tissue diagnosis is possible with open biopsy and stereotactic biopsy.
Source: WHO classification of CNS tumors, 4th Ed. 2007 and 2016 update
Primary CNS lymphomas ( PCNL) were first described by Bailey in 1929 as "perithelial sarcoma."
Primary CNS lymphoma constitutes about 3% of all brain tumors.
Most are large B-cell lymphomas , only 2% of T-cell origin.
PCNL affects all ages, with a peak incidence in immunocompetent subjects during the sixth and seventh decade of life.
In immunocompromised patients, the age at manifestation is lowest in individuals who have an inherited immunodeficiency ( 10 years ) , followed by transplant recipients ( 37 years ) and AIDS patients ( 39 years ).
Common location is the brain parenchyma surrounding the ventricular system, but any craniospinal structure can be involved. AIDS epidemic led to increase in the incidence of Lymphoma. The clinical manifestations are similar to other intracranial space occupying lesions of the brain and like other brain tumors CT scan and MRI with contrast and MR spectroscopy helps to diagnose these tumors.
Majority of patients present with focal neurological deficit. Some patients present with features of raised intracranial pressure like headache and vomiting. Few patients present with neuropsychiatric symptoms and seizures. Eye symptoms due to uveitis or vitreous lymphoma may occur in about 5 percent cases. Dementia may also be a symptom of cns lymphoma.
About 50% of transplantation associated primary cns lymphomas appear within a year after transplantation.
PCNSL occur as a single or multiple masses in in deep location in cerebral hemisphere or in the peri ventricular region. It may be diffuse or well demarcated. Diffuse infiltrative form may present as lymphomatous cerebri. Meningeal lymphoma may present as meningioma or meningitis.
On CT scan it is infiltrative lesion with indistinct margins and isodense or hyperdense with homogeneous enhancement with minimal surrounding edema or compressive effect. Solitary lesion in majority of cases. Lesions are usually supratentorial and localized in the deep periventricular areas.
Clinical presentation is similar to any other space occupying lesion. Steroid , cerebral decongestants and antiepileptic medication are given and a tissue diagnosis is possible with open biopsy and stereotactic biopsy.
2016-
World Health Organization (WHO) classification of CNS tumors has classified the
Lymphomas of the central nervous system as follows:
Diffuse
large B-cell lymphoma of the CNS
Immunodeficiency-associated
CNS lymphoma
AIDS-related
diffuse large B-cell lymphoma
EBV-positive
diffuse large B-cell lymphoma, NOS
Lymphomatoid
granulomatosis
Intravascular
large B-cell lymphoma
Low-grade
B-cell lymphoma of the CNS
T-cell
& NK/T cell-lymphoma of the CNS
Anaplastic
large cell lymphoma , ALK-positive
Anaplastic
large cell lymphoma , ALK-negative
MALT
lymphoma of the dura
Source: WHO classification of CNS tumors, 4th Ed. 2007 and 2016 update
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