MRI features and differential diagnosis of AIDS-related intracranial lymphoma

XUE Ming; LI Jingjing; YAN Shuo; LYU Zhibin; CUI Tao; CHEN Qiyi; ZHANG Zixin; DU Yanni; XIE Ruming

Abstract：Objective To explore the MRI imaging features of AIDS-related intracranial lymphoma in order to improve the level of diagnosis and differential diagnosis of this disorder. Methods MRI imaging data of 15 patients with AIDS-related intracranial lymphoma, who were confirmed by surgery and pathology in Beijing Ditan Hospital from July 2013 to October 2017, were retrospectively analyzed and the MRI imaging characteristics of this disorder were summarized and analyzed in combination with literature. Results The pathological types of those 15 patients were all B cell lymphoma, in which the diffuse large B cell lymphoma (diffuse large B-cell lymphoma, DLBCL) was found in 11 cases and Burkitt's lymphoma (Burkitt lymphoma, BL) in 4 cases. The multiple lesions were the major type (with respect to 32 focuses, Meningeal type was found in 2 cases), which was located around the midline or ventricle, with invasion into cortex and involvement of gray matter. In this group, there were 4 cases of single lesion, 9 cases of multiple lesions, and 2 cases of meningeal type. 9 cases were located in supratentorial area, 2 in infratentorial area and 1 case in both infratentorial and supratentorial area with multiple lesions. MRI showed different shapes of focuses, such as a solid or cystic mass, multiple nodules, irregular spots, patchy lesions. DWI lesions were limited to different degrees, which exhibited the irregular high signal ring, with the decrease in ADC value. T1WI showed that 10 patients (12 lesions) presented with irregular high signal or slightly high signal. After the enhanced scan, the lesions showed the mass-like, nodular or patchy enhancement, irregular thick wall ring enhancement or peripheral ring enhancement. There was mild edema or no edema. 3 cases appeared severe edema, and 1 case exhibited the prostrate growth along the ependyma, and 1 case showed ependymal dissemination. Conclusion MRI imaging features of AIDS-related intracranial lymphoma are complex and various, and may have certain characteristics. However, some lesions are atypical, which are easily confused with toxoplasmosis and other diseases. We must carefully analyzed the MRI imaging signs combined with clinical findings, which helps to improve the diagnostic accuracy.