Introduction: The present study aimed to characterize the MRI features of intracranial primary central nervous system
lymphoma (PCNSL) in the Malaysian population, and to compare the findings with other population-based studies.
Methods: Twenty-four patients with histologically confirmed PCNSL from 2008 to 2014 were identified. Eighteen patients had MRI images at presentation available for review. The images were reviewed by two radiologists, noting the
number, size, location, signal characteristics, perilesional oedema and characteristics of enhancement of the lesions.
Results: Ten patients had solitary lesions, while 8 patients had multiple lesions with a total of 31 lesions. The lesions
were mostly located in the frontal lobe and basal ganglia. Most lesions were hypointense on T1 sequences, hyperintense on T2 sequences, with moderate to marked perilesional oedema. All lesions showed contrast enhancement.
Five lesions demonstrated the ‘notch sign’, 1 lesion showed ‘open-ring’ pattern of enhancement and 1 lesion had
a non-enhancing core. Seventeen lesions demonstrated an uneven enhancement pattern, mainly in lesions that are
abutting the ventricular margins. Conclusion: MRI findings of patients with PCNSL in our population concur with
other population-based studies. Enhancement patterns like the ‘notch sign’, ‘open-ring’, and uneven enhancement
are not uncommon in PCNSL.