少见部位原发性结外淋巴瘤的影像学特征

Imaging features of primary extranodal lymphoma in the rare sites

目的:探讨少见部位原发性结外淋巴瘤的影像学特性,提高影像诊断的准确性。方法:回顾性分析26例经病理证实的原发性结外淋巴瘤的临床及影像学资料,所有病例初诊时均无其他部位淋巴瘤病史,其中19例仅行CT检查,3例仅行MRI检查,4例同时行上述两项检查。结果:26例结外淋巴瘤中,发生于眼眶、腮腺、肾上腺、睾丸者,病灶密度/信号均匀,增强后呈轻中度延迟强化,眼眶病变可沿眼眶间隙蔓延呈塑形生长、亦可包绕眼环呈光芒样改变,腮腺病变均多发,肾上腺病变可保留原有肾上腺形态;发生于肺者,病变均侵犯双侧,CT表现多样化,病灶内可见空气支气管征及含气空腔,病灶周围呈磨玻璃样改变;发生于骨骼者,表现为骨质破坏轻、周围软组织块巨大,且病灶密度/信号均匀;发生于肝脏者,病灶均单发、位于肝脏周边,边缘模糊,密度均匀或不均,增强后呈中度延迟强化或环形强化。结论:结外淋巴瘤尽管发病部位不同,但有较明显的影像学共性;部分少见部位结外淋巴瘤具有各自的影像学特征,需要与其他病变鉴别。

Objective： To observe the imaging features of primary extranodal lymphoma in the rare site involvement for improving the diagnostic accuracies.Methods：Imaging features were retrospectively examined in 26 cases of primary extranodal lymphoma confirmed in surgery and by pathology.History of other site of lymphoma was free in all cases upon initial diagnosis.Nineteen cases underwent CT examination,3 MRI detection,and another 4 cases received examination with both CT and MRI.Results：Rare sites of extranodal lymphomas in the 26 cases were involved in orbit,parotid gland,adrenal gland and testis.The imaging density and signals were uniform,and presented with low to middle degree dynamically delayed enhancement.The cases with lesion in orbit were seen infiltration into intraorbital tissues along with extra ocular muscle or enclosing the eye thimble,demonstrating ＂light-casting＂ sign.Extranodal disease in the parotid gland was presented with multiple lesions,yet the adrenal gland remained original configuration in cases of lesions in adrenal involvement.Bilateral lung tissues were involved in lesions in the lung where demonstrated diverse CT imaging findings,including visible air bronchogram and cystic airspace,and the lesions were surrounded by ground-grass opacity.The imaging findings for lesions in bones were presented with minor marrow cavity destruction and large mass in the soft tissues surrounding the bones.The density and signals were uniform at the lesion.Extranodal lesion in the liver was single and localized at the liver edge,with faint margin and uniform or uneven density,which presented moderate degree dynamically delayed or ring enhancement.Conclusion：Although extranodal lymphoma may occur in different site,yet it has similarities in imaging demonstrations.However,certain rare site of extranodal lymphoma should be differentiated from other extranodal disease due to its distinct features in imaging.