原发性中枢神经系统淋巴瘤的影像学表现与病理对照

Characteristic imaging features of primary central nervous system lymphoma in comparison with pathological findings

目的探讨原发性中枢神经系统淋巴瘤(PCNSL)的影像学特征。方法回顾性分析13例经手术或穿刺病理证实的PCNSL患者的影像学资料和病理资料。其中5例行CT检查,6例行MRI检查,1例同时行CT、MRI检查,1例同时行MRI及PET/CT检查。结果13例PCNSL中,单发11例、多发2例;幕上9例、幕下3例,弥漫分布1例。6例CT平扫呈等或稍高密度,增强后轻中度强化。7例MRI检查T1WI呈等低信号,T2WI呈等或稍低信号;Gd-DTPA增强后5例呈明显均匀强化,2例病灶中心伴有小囊变区;其中5例见"尖角征"、4例见"脐凹征"。除1例弥漫型病变外余12例均伴有轻中度占位效应和瘤周水肿。1例弥漫型病变呈长T1长T2改变,增强后呈明显结节样强化,PET/CT示18F-FDG明显高摄取。病理示肿瘤呈灰白或灰红色,质软,无包膜,血运较丰富,镜下见瘤细胞多围绕在血管周围呈簇状分布。结论PCNSL影像学表现有一定特征,可对临床有提示性诊断,必要时可立体定位穿刺活检。

Objective To investigate the imaging features of primary central nervous system lymphoma （PCNSL）. Methods The imaging and pathological findings in 13 patients with pathologically confirmed PCNSL were analyzed retrospectively. Of these patients, 5 underwent CT scan, 6 had magnetic resonance imaging （MRI） examination, 1 patient underwent both CT and MRI examinations, and another had both MRI and PET/CT examinations. Results Among the 13 patients with PCNSL, 11 were identified to have solitary tumor foci and the other 2 had multiple lesions. Supratentorial tumors were found in 9 patients, infratentorial tumors in 3 patients, and both supratentorial and infratentorial tumors in 1 patient. In 6 cases, the tumor presented isodensity or slight hypodensity on plain CT images, with mild or moderate enhancement after contrast agent injection. The lesions showed isointense or hypointense signals on T1WI and isointense or slightly hypointense signals on T2WI in 7 cases, with obvious homogenous enhancement in 5 cases and microcystic loci in 2 cases after gadolinium injection. Five patients showed the ＂angular sign＂ and 4 the ＂hilar depression sign＂. All the patients presented with mild or moderate peritumoral edema and space-occupying mass except for 1 patient with diffuse lesions, who showed hypointense signals on T1WI and hyperintense signals on T2WI with obvious nodular enhancement after gadolinium injection and high ^18F-FDG uptake on PET/CT. Pathologically, the tumors appeared pinkish or grey-white, soft, with rich blood supply and without capsules. The tumor cells were found to cluster around the blood vessels under microscope. Conclusion PCNSL may present with typical imaging features wihich can he suggestive of the diagnosis. Stereotactic biopsy can be performed when necessary to obtain a definite diagnosis.