Assessment of primary brain lymphoma using multimodal magnetic resonance imaging and proton magnetic resonance spectroscopy

Abstract

Objectives:The primary lymphoma of the central nervous system is a cancer rare. The diagnosis of this tumoral entity must be considered as an emergency considering the therapeutical involved. Therefore, we report this entity while reporting diagnostic challenges.Patients and Methods:Unfortunately, the conventional clinical and imaging signs can be confusing and might contribute to delay the diagnosis process of potentially curable pathological entity. The diagnosis confirmation in immunocompetent patients is based on a stereotaxic biopsy.Results and Conclusion:In this paper, we report a case illustrating the contribution of multimodal imaging including diffusion-weighted magnetic resonance imaging (MRI), diffusion tensor MRI, perfusion MRI, and proton MR spectroscopy to the diagnostic approach of the atypical primary lymphoma of the central nervous system.

Primary large B-cell lymphoma involving the cerebellopontine angle mimic acoustic schwannoma: Role of MR Spectroscopy in differential diagnosis. A case report

“…The ratios between the various metabolites were: NAA/Cr = 1.57, Cho/Cr = 7.09, NAA/Cho = 0.22, Cho/NAA = 4.50. These MRS findings were quite similar to primary CNS lymphoma magnetic resonance spectroscopy (MRS) features, which are a significant rise of choline, NAA, and creatine decrease, high Choline/Creatine (Cho/Cr) and Choline/N-acetylaspartate (Cho/NAA) ratios and lipidic peak [ 2 , 3 , 5 , 7 ]. MRS helps to differentiate primary CNS lymphoma from other lesions, such as acoustic neuroma and meningioma: in fact, acoustic neuroma shows myo-inositol peak and high choline peak; myo-inositol peak is maybe related to microglial activation and astrogliosis, a feature that is observed in this lesion [ 2 , 3 , 11 ].…”

“…Cerebellopontine angle tumors are a varied group of neoplasms: the most common CPA tumor is acoustic neuroma, also called vestibular schwannoma. The second most common CPA neoplasm is meningioma [ 7 , 12 ]. Primary CNS lymphoma is a rare tumor and primary cerebellopontine angle lymphoma is much rarer, only 15 cases of large B-cell lymphoma at the CPA have been reported worldwide [ 4 , 6 , 8 ], and no cases studied with MR Spectroscopy.…”

“…Meningiomas do not generally show restricted diffusion on DWI, except grade II-III meningiomas [3] . CNS lymphoma shows restricted diffusion in DWI and low apparent diffusion coefficient (ADC) values because this neoplasm is highly cellular, but restricted diffusion may also be observed in acute ischemic stroke, central necrosis of brain abscesses, solid portion of high-grade gliomas, some metastases and grade II-III meningiomas [ 2 , 3 , 7 , 10 ]. In the few cases of diffuse large B-cell lymphoma of the CNS studied with MR Spectroscopy (not specifically of the PCA) MRS revealed a decrease in N-acetyl aspartate (NAA) peaks, as well as an inversion of the choline/creatinine and choline/NAA ratios and the presence of Choline peaks, indicating cell proliferation.…”

“…It is often not detectable on Imaging Diagnostic tools and cerebrospinal fluid cytology allows for diagnoses this disease more readily [3] . Primary CNS lymphoma is a very rare aggressive non-Hodgkin disease that originates in CNS (brain, leptomeninges, spinal cord, or eyes), it seems to have increased over the last two decades in both immunocompromised and immunocompetent patients [ [2] , [3] , [4] , [5] , [6] , [7] , [8] ]. An early and accurate diagnosis of this neoplasm is necessary for the best management because it is a radiosensitive and chemosensitive tumor [2] .…”

“…Magnetic resonance imaging (MRI) is the gold standard imaging diagnostic tool to evaluate cerebellopontine angle masses and it is considered the method of choice to diagnose and follow-up primary CNS lymphoma [ 2 , 4 , 8 , 10 , 11 ]. Radiological features of this tumor are not specific in conventional MRI and advanced imaging techniques, such as diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), magnetic resonance perfusion (MRP), and MR spectroscopy (MRS) have revealed themselves as useful to differentiate primary CNS lymphomas from other neoplasms [ 2 , 3 , 7 ]. In our case, MR Spectroscopy played an important role to diagnose a primary lymphoma of CPA and differentiate it from an acoustic schwannoma or meningioma.…”