纵隔原发性精原细胞瘤的CT表现

摘要

目的 探讨纵隔原发性精原细胞瘤的CT表现.方法 回顾分析10例经病理证实的、原发于纵隔精原细胞瘤的临床、病理及CT资料.结果 10例病灶均单发,前纵隔8例,前中纵隔1例,1例位于前纵隔-心包区;最大径范围:8～13cm,中位数:11cm;类圆形/卵圆形6例,不规则形4例;局部边界不清;8例为单纯精原细胞瘤,CT平扫显示肿块呈均匀等密度,其中3例并外周小囊变,1例病灶中央见点状钙化,增强后呈轻度较均匀强化,5例病灶内见条状血管影,病理组织学检查,镜下为纤维血管间隔;2例为内胚窦瘤为主(60％～70％),伴精原细胞瘤,CT平扫/增强病灶呈“类蜂窝状”改变,内见明显坏死、囊变影;所有病例均未见肿大淋巴结及肺内、外转移.3例上腔静脉明显受压变窄;2例肿块呈灌注样生长,填充前上纵隔间隙,纵隔血管于肿块内呈“漂浮状”;6例合并胸腔积液,2例同时并心包积液,其中1例侵犯心包;8例出现β-HCG轻-中度升高,其中2例同时伴AFP明显升高.结论 青少年男性、前纵隔占位,肿块巨大,而密度却较均匀,强化较轻微、特别是肿块呈灌注状生长、病灶内出现纤维血管间隔,结合βΝ-HCG升高,排除继发,应考虑该病诊断.%Objective To explore the CT features of primary mediastinal seminoma.Methods We retrospectively analyzed the CT images of 10 patients with primary mediastinal seminoma confirmed by pathology who underwent multislice helical CT plain scaning and enhancement scanning before operation.Resnlts The lesions of 10 cases were single,located in the anterior mediastinum in 8 cases,anterior middle mediastinum in 1 case,and anterior mediastium pericardial area in 1 case.Median size of the tumors was 11 cm (ranging from 8 to 13 cm).All of the lesions were ill-defined with 6 being round or ovoid and 4 being irregular.There were 8 pure seminomas.Unenhanced CT showed uniform isodensity and enhanced CT scan showed slight enhancement.Calcification and small cystic component were found in 1 case and 3 cases,respectively.Strip vasculars can be seen in 5 cases.And Histologically,it was proved to be fiber vascular interval hyperplasia.2 cases were proved as endodermal sinus tumors accompanying with seminomas by pathological results,and showed nonuniform low intensity,with a honeycomb-like change.None had swelling lymph nodes or metastasis.3 tumors compressed superior vena cave in a serious degree; 2 tumors filled the mediastinal spaces,with a perfusion shape growth,and the mediastinal vessels within the tumors showed "floating sign".6 cases had pleural effusion and 2 cases had pericardial effusion (1 case invaded pericardium); The β-HCG was slight or moderate increased in 8 cases.Meanwhile,the AFP was increased significantly in 2 cases.Conclusion The disease should be considered for primary mediastinal seminoma,combined with the increasing of β-HCG,a large tumor of the anterior mediastinum in a young adult male,with a uniform isodensity and slight enhancement,perfusion shape growth and fiber vascular interval.