肌内法瓦病的MRI表现及病理对照分析

MRI findings and pathological analysis of intramuscular fibro-adipose vascular anomaly

目的探讨肌内法瓦病(FAVA)的MRI表现及其病理特征。方法回顾性分析2012年12月至2021年3月于河南省人民医院就诊的44例经病理证实的肌肉内FAVA的临床及影像资料,女25例、男19例,年龄5~29(15±6)岁。总结其临床及MRI特征,包括分型、部位、边界、信号强度、强化方式及程度、病变内有无血管流空,并与病理结果对照。结果 1例患者大腿及小腿肌肉同时受累,43例患者病变累及1个部位,包括小腿肌肉20例、大腿肌肉15例、前臂肌肉5例、上臂肌肉1例、臀肌1例、肩部肌肉1例。小腿腓肠肌受累最多见(13/44),其次为比目鱼肌(10/44)、股四头肌(9/44)。MRI示病变均为实性病变,其中局灶肿块型24例、弥漫浸润型15例、局部浸润型5例。病变的长轴均与肌肉长轴一致。T1WI及T2WI均呈不均匀中等高信号,脂肪抑制T2WI呈显著高信号,所有病变均可见迂曲扩张的畸形血管,其中18例可见流空血管影。增强后呈中等至明显不均匀强化。病理学上,病变的骨骼肌被纤维组织、脂肪成分、不规则的畸形静脉血管等多种成分浸润,导致MRI信号的不均匀。7例接受人类PIK3CA基因突变检测者中6例为突变型。结论肌内FAVA在临床、MRI影像以及组织病理学上均具有一定的特征性,其MRI信号特征可反映其复杂的病理成分。

Objective To investigate the MRI and pathological features of intramuscular fibro-adipose vascular anomaly(FAVA).Methods The clinical and imaging data of 44 patients with intramuscular FAVA confirmed by pathology from December 2012 to March 2021 in Henan Province People′s Hospital were retrospectively analyzed.Twenty-five females and 19 males were included,with the age of(15±6),from 5 to 29 years old.The clinical and MRI features including the type,location,boundary,signal intensity,enhancement mode and degree,and the vascular flow voids in the lesion were summarized and compared with pathological results.Results The thigh and calf muscles were involved in 1 patient simultaneously,and 1 site was involved in 43 patients,including 20 calf muscles,15 thigh muscles,5 forearm muscles,1 upper arm muscle,1 gluteal muscle,and 1 shoulder muscle.The gastrocnemius muscle of lower leg was most commonly involved(13/44),followed by soleus muscle(10/44)and quadriceps femoris muscle(9/44).All the lesions were solid on MRI,including 24 cases of focal mass type,15 cases of diffuse infiltration type and 5 cases of local infiltration type.The long axis of all the lesions were consistent with the long axis of the muscles.All lesions showed inhomogeneously moderate hyperintensity on T1WI and T2WI,and significantly hyperintensity on fat suppression T2WI.All lesions showed tortuous and dilated abnormal vessels,of which 18 cases showed vascular flow voids.Thrombosis was found in 10 cases.On contrast-enhanced imaging,the lesions showed moderate to obvious inhomogeneous enhancement.Pathologically,the diseased skeletal muscle was infiltrated by fibrous tissue,fat components,irregular abnormal veins and vessels,which led to inhomogeneous MRI signals.Among the 7 patients who underwent human PIK3CA gene mutation detection,and 6 were mutant.Conclusions Intramuscular FAVA has certain characteristics in clinic,MRI imaging and histopathology,and its MRI signal characteristics can reflect its complex pathological components.