Atypical MRI presentation of primary central nervous system non-hodgkin lymphoma / 中华放射学杂志

ABSTRACT

Objective To investigate the atypical MRI manifestations in patients with primary central nervous system lymphoma(PCNSL). Methods The clinical and MRI manifestations of 17 patients with pathologically confirmed atypical PCNSL in the First Affiliated Hospital of Henan University of Science and Technology (from May 2011 to Dec 2016) and Nanfang Hospital (from Sep 2003 to May 2009) were analyzed retrospectively in this study. Both conventional and contrast-enhanced MR images were acquired for each patient. The MRI manifestations including the number, location, size, shape, signal intensity, enhancement patterns of lesions were evaluated by two senior radiologists.Results Of the 17 cases,8 were solitary and 9 were multiple.Two types of atypical MR findings were found(1)Atypical locationFor the 9 patients showed atypical location,7 patients had solitary masses which were located in the brainstem(n=3), the supratentorial superficial parts(n=2), the cerebellum(n=1)and the sella(n=1). Two patients had multiple lesions, showing multiple subependymal nodules and no abnormalities in the brain parenchyma. Six of the 7 solitary lesions and the 2 multiple cases showed isointense or hypointense on T1-weighted scans and isointense or hyperintense on T2-weighted scans as well as significant homogenous enhancement on contrast-enhanced T1-weighted scans.(2)Atypical signal featuresTen cases were found with atypical signal features including①Patchy lesions were observed in 6 patients( one patient with single lesion, and five patients with multiple lesions),appearing as hyperintense spots on T2-weighted image and subtle hypointense on T1-Weighted image. Corresponding contrast-enhanced T1-weighted MR image showed multiple patchy/linear enhancement. ②Two cases showed diffuse supratentorial periventricular and infra-tentorial white matter T2hyperintensity and absence of contrast enhancement. ③Nodular lesions with inhomogeneous internal signals were found in 2 cases with calcification(n=1) and cystic necrosis (n=1, ring-like enhancement).Conclusions The atypical imaging manifestations of PCNSL could lead to misdiagnosis or delay in the diagnosis.It is important to understand its atypical imaging features and combine with clinical manifestations to improve the accuracy of differential diagnosis of intracranial lesions.