鼻咽非霍奇金淋巴瘤的MRI表现与侵犯特点

Non-Hodgkin lymphoma at nasopharynx： features of MRI

目的探讨鼻咽非霍奇金淋巴瘤（NHL）的MRI表现特征及鉴别诊断。方法回顾性分析41例经病理证实的鼻咽NHL的MRI表现。评价病灶的大小、分布、侵犯范围及淋巴结累及情况。对B细胞型和T或NK／T细胞型2组NHL的侵犯生长方式比较采用Fisher确切概率法或Pearson卡方检验。结果41例患者中，成熟B淋巴细胞肿瘤26例，成熟T淋巴细胞肿瘤2例，NK／T细胞瘤13例。病灶以鼻咽黏膜增厚或形成软组织肿块为主要表现，在T：WI上呈稍高信号，T，wI呈等信号，增强后均匀轻到中度强化。均匀累及鼻咽各壁24例，伴溃疡形成5例，超腔生长9例，累及舌或腭扁桃体共23例，邻近肌肉受侵20例，颅底骨质破坏12例。41例患者中，25例合并咽后淋巴结受侵，27例合并颈部淋巴结受侵。NK／T淋巴细胞型鼻咽NHL更易超腔生长、咽旁结构侵犯、溃疡形成（T或NK／T淋巴细胞型鼻咽NHL分别为8、11、4例，B淋巴细胞型鼻咽NHL分别为4、10、1例），B淋巴细胞型鼻咽NHL扁桃体侵犯更常见（B淋巴细胞型鼻咽NHL为18例，NK／T淋巴细胞型鼻咽NHL为5例）。结论鼻咽NHL在MRI上表现具有一些特点，鼻咽各壁均匀增厚多见，常累及鼻腔或扁桃体，当肿瘤体积较大但没有或仅有少许深度侵犯时要考虑NHL。不同病理类型鼻咽NHL其MRI表现有一定差异。

Objective To characterize the features of Nasopharyngeal non-Hodgkin＇s lymphoma （NHL） on MR imaging and find the main points to differentiate it from the other nasopharyngeal tumors. Methods, The MR images of 41 patients with pathologically and immunohistochemically proven nasopharyngeal NHLs were reviewed retrospectively. Images were assessed by the size, invasive extent, signal intensity of primary nasopharyngeal tumor, and the distribution of cervical lymphadenopathy. The difference of regional tissues invasion and cervical lymphadenopathy distribution between the patients with B-cell NHLs and the patients with T-cell or NK/T-cell NHLs were analyzed by Pearson＇s Chi-Square test or Fisher＇s exact test. Results Of the 41 patients, 26 patients had mature B-cell lymphoma, two patients with mature T-cell lymphoma, and thirteen patients showed Nature killer/T-cell lymphoma in nasopharynx. MRI revealed that NHLs of nasopharynx can be showed as thickening of nasopharyngeal mueosa and （or） lumps in nasopharynx, which were slightly hyper-intensity on T2-weighted images, and intermediate signal intensity （similar to muscle） on Tl -weighted images, with mild or moderated enhancement following contrast medium administration. Twenty four cases had symmetrical disease of all walls of nasopharynx, and 17 cases had unsymmetrical tumor. Of all cases, 5 cases had superficial ulcerations, 9 cases had exceed nasoharynx invasion spreads superficially along the mucosa, 23 cases had invasion of lingual and （or） palatine tonsils, 20 cases showed invasion of parapharygeal muscles, 12 cases suffered from skull base bone infiltration, 25 cases had retropaharyngeal lymphadenopathy, and 27 cases had cervical lymhadenopathy. Patient with nasopharyngeal Nature killer/T-cell lymphoma had a higher incidence of exceed nasopharynx invasion, parapharyngeal structures invasion, and superficial ulcerations （ the cases were 8, 11, 4 in patient with T-cell or NIL/T-cell lymphoma, and 4, 10, 1 in patients with B-cell lymphoma, respectively）. Patients with nasopharyngeal B-cell lymphoma had a higher incidence of inasion of lingual and （ or ） palatine tonsils. Conclusions Nasopharyngeal NHL is a homogeneous tumor that tends to diffusely involve all walls of the nasopharynx and spread in an exophytie fashion to fill the airway, rather than infiltrating into the deep tissues. Different pathological types of nasopharyngeal NHLs have some different appearance on MRI between each other. A large tumor in nasopharynx that fills the nasopharynx cavity, with no or minimal invasion into deep structures, but with invasion extend down into the lingual and（or） palatine tonsils, may suggest the diagnosis of nasopharyneal NHL.