炎性肌纤维母细胞瘤的影像学诊断

Imaging diagnosis of Inflammatory myofibroblastic tumor

目的:探讨炎性肌纤维母细胞瘤(IMT)的CT和MRI表现及其临床诊断价值。方法:回顾性分析经手术病理证实的20例IMT患者的CT和MRI表现,其中14例行CT检查,6例行MRI检查。结果:20例中病变发生于肺部8例、会厌部1例、鼻腔1例、腘窝1例、胸壁2例、臀部2例、下颌磨牙区1例、膀胱1例、浅表软组织3例。肺内病变3例为中央型,CT表现为边界不清的实变灶;5例为周围型,表现为边界清楚的软组织密度肿块或结节。肺外病变表现为不同部位实性肿物或结节。MRI表现为稍长T_1稍长T_2信号的软组织肿块;增强扫描后肿块实性部分呈均匀或不均匀中度或明显强化,坏死、囊变区无明显强化。病理示肿瘤由梭形细胞及炎细胞组成,免疫组织化学染色肌源性蛋白阳性表达。结论:IMT是一种少见的肿瘤,CT和MRI检查能为其提供准确的解剖部位等信息,在定性诊断方面有一定价值,但最后确诊还有赖于组织病理学及免疫组织化学检查。

Objective： To investigate the CT and MRI features of inflammatory myofibroblastic tumor（IMT）and their value in the clinical diagnosis. Methods： The CT and MRI findings of 20 cases with pathology proven IMT were retrospectively analyzed, of which, 13 cases had CT and 5 cases had MRI. Results： The anatomic locations of tumors in these 20 patients included lung （ n =8）, epiglottis（ n =1）, nasal cavity （ n =1）, popliteal fossa（ n =1）, chest wall（ n =2）, buttocks（ n =1）, mandibular molar（ n ： 1）, bladder（ n = 1）, superficial soft tissue（ n = 3）. In terms of lung lesions, there were 3 central lesions presented as solid masses with obscure boundary margin; 5 peripheral lesions as solid masses or nodules with well-defined margin. The lesions out of the lung presented as solid masses or nodules in diverse sites. MRI appearance was mass of a slightly-long T1 slightly-long T2 signal. After contrast enhancement,moderate or marked homogeneous or heterogeneous enhancement were shown in the solid part of tumor, cystic and necrotic without marked enhancement. Tumors were mainly composed of spindle shaped fibrous cells and inflammatory cells on pathology. On immunohistochemistry staining, positive expression of muscle deriving proteins was observed. Conclusion： The final diagnosis of IMT relies on pathology and immunohistochemistry study, CT and MRI examination provides information of accurate anatomic location and are helpful for the clinical diagnosis.