"Historically there has been a strong association with HIV/AIDS and other immunocompromised states and demographics in these patients reflect the underlying condition – see immunodeficiency-associated CNS lymphomas."
"Primary CNS lymphomas in immunocompromised patients (typically HIV/AIDS or post-transplant), or other types of lymphoma, may be more heterogeneous in appearance. For example, in immunocompromised individuals, central non-enhancement/necrosis and haemorrhage are more common, although the latter is still uncommon – see immunodeficiency-associated CNS lymphomas 8."
"Classic imaging appearance for primary CNS lymphoma is of a CT hyperdense avidly enhancing mass, with T1 hypointense, T2 iso- to hypointense, vivid homogeneous gadolinium-enhancing lesion(s) with restricted diffusion on MRI, and exhibiting subependymal extension and crossing of the corpus callosum 17."
"T1: typically hypointense to grey matter 9"
"T2: variable"
"restricted diffusion with ADC values lower than a normal brain, typically between 400 and 600 x 10-6 mm2/s (lower than high-grade gliomas and metastases 8,13)"
"restricted diffusion with ADC values lower than a normal brain, typically between 400 and 600 x 10-6 mm2/s (lower than high-grade gliomas and metastases 8,13)"
"Carbon-11 methionine PET"
"anaplastic large cell lymphoma (ALK+/ALK−)"
"anaplastic large cell lymphoma (ALK+/ALK−)"
"T-cell and NK/T-cell lymphomas"
"There has been an increase in the incidence of sporadic, non-EBV-associated primary CNS lymphomas in immunocompetent individuals, which is particularly seen in older patients (50-80 years of age) 14."
"Diffuse large B-cell lymphoma, which is the most common, is characterised by immunohistochemical reactivity for CD19, CD20, CD22, CD79a and PAX-5 14."
"CSF examination demonstrates elevated protein and decreased glucose. Positive cytology is uncommon (~25%). Positive EBV DNA in CSF is helpful for the diagnosis of lymphoma, particularly in immunocompromised individuals."
"While this typical pattern is helpful in diagnosis, it is predominantly observed in untreated non-immunocompromised patients; diffuse large B-cell lymphoma, EBV negative 17."
"markedly decreased NAA"
"butterfly glioma/GBM"
"tumefactive MS/ADEM"
"The remainder of this article presents a general discussion of primary diffuse large B-cell lymphoma of the CNS, which is by far the most common type of CNS lymphoma, accounting for 80-85% of cases 17. Other types are discussed separately."
"in superficial lesions with cortical involvement, a cortical diffusion-enhancement mismatch sign has been suggested as highly specific, defined as the lesion having diffusion restriction that involves both gray and white matters but with the corresponding gadolinium-enhancement only involving the subcortical white matter 29,30"
Expected headings
"Effects of steroids"
"CSF"
"Thallium-201 scintigraphy"
"Fluorine-18 FDG PET"
"Carbon-11 methionine PET"
"On imaging, primary diffuse large B-cell lymphoma of the CNS typically appears as a CT hyperattenuating, enhancing mass, usually supratentorial, with MRI T1 hypointense, T2 iso- to hypointense, vivid homogeneous enhancement and restricted diffusion. Usually, there is relatively little associated vasogenic oedema and no central necrosis."
"Typically, patients diagnosed with primary CNS lymphoma are over the age of 50 years with a short duration of symptoms (at most a few months) 4. There is a male predominance of approximately 2:1 4."
"There is increasing evidence that in selected patients (those with accessible solitary lesions) local treatment with surgical resection may significantly improve survival 1,20-22."
"Patients with primary CNS lymphoma present similarly to patients with other central nervous system masses; symptoms and signs of raised intracranial pressure, focal neurological disorders and seizures. If ocular involvement is present then changes in vision may be present 25."
"While this typical pattern is helpful in diagnosis, it is predominantly observed in untreated non-immunocompromised patients; diffuse large B-cell lymphoma, EBV negative 17."
"note: low T2 signal may result in lower b=1000 signal despite low ADC values; blackout effect 17"
"The tumours are often high-grade and, despite treatment, have a poor prognosis. If only surgical resection is performed, then death occurs within a few months. With high-dose chemotherapy, the tumour can be significantly reduced in size; however, recurrence is common, with a median survival of around 30 months 1. Those who are immunocompromised (e.g. have HIV) have worse outcomes. Baseline higher metabolic tumour volume and higher lesion glycolysis evaluated with PET imaging has been associated with shorter progression free survival and poorer overall survival 27."
"Diffuse large B-cell lymphoma, which is the most common, is characterised by immunohistochemical reactivity for CD19, CD20, CD22, CD79a and PAX-5 14."
"contrast enhancement is absent, irregular or only mild"