Modern techniques of magnetic resonance in the evaluation of primary central nervous system lymphoma: contributions to the diagnosis and differential diagnosis

Abstract

In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence.This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

Primary dural diffuse large B cell lymphoma mimicking parafalcine meningioma

“…Clinically also, they share multiple features including being more common in women, similar age group and clinical presentation (headache, seizures, focal neurological deficits, meningeal signs and sometimes cranial nerve involvement) 4 7 11 12. The presence of lipid/lactate and choline peaks with reduced N-acetylaspartate on MR spectroscopy (as in our case) favours primary dural lymphoma over meningioma and is associated with a poor prognosis 13. Nearly all previously reported cases of diffuse large B cell primary dural lymphoma were found to be associated with lytic bony involvement and vasogenic oedema of adjacent brain parenchyma; however, our case is unique in the sense that it involved falx cerebri away from calvarial bones and in addition to extensive brain parenchymal oedema; it also showed the presence of haemorrhage within the mass on histopathology, which was picked up beforehand on susceptibility-weighted MRI as areas of blooming in the central part of the mass.…”

Lymphomatosis cerebri: a rare variant of primary central nervous system lymphoma and MR imaging features

“…DWI reflects the motion of intra- and extra-cellular water. It is helpful in distinguishing between PCNSL and other tumors and tumor-mimicking lesions [ 18 ]. Highly cellular tumors, like central nervous system(CNS) lymphoma, generally present as single or multiple contrast-enhancing mass lesions on MRI scans, with hyperintensity on DWI and hypointensity on ADC maps [ 19 ].…”

“…In PCNSL,MRS has demonstrated elevated Lip and Lac peaks, high Cho/Cr ratios, decreased NAA levels and high Cho/NAA ratios [ 21 , 22 ]. PCNSL grows rapidly and behaves similar to other high-grade brain tumors with evidence of high cell membrane turnover on MRS(high Cho peak), neuronal damage (decreased NAA levels), and anaerobiosis (high lactate levels) [ 18 , 19 , 22 ].These findings are similar to those for high-grade gliomas and metastases; however, MRS is useful to suggest PCNSL because lipids were found to be useful to discriminate between PCNSL and glioblastoma/metastasis at short TE [ 23 ].In our three LC patients, MRS (at TE 135 ms or 40 ms) consistently presented a pattern of marked decrease of NAA/Cr, increase of Cho/Cr, which is suggestive of malignant neoplastic disease. Two patients showed increased Lip/Cr and Lac/Cr.…”

Magnetic Resonance Spectroscopy and its Clinical Applications: A Review

“…Prominent Cho signal combined with reduced NAA levels is a sign of this disease. Lac changes in different studies were inconsistent in different studies (Figure 13) [140,141].…”