小儿外周原始神经外胚层肿瘤的MSCT诊断

目的分析小儿外周原始神经外胚层肿瘤(pPNET)的MSCT表现,提高对该病的认识。方法回顾性分析11例经病理确诊的pPNET的MSCT表现。结果 8例巨大软组织肿块伴骨质破坏,其中3例表现为骨质放射状增生伴局部骨质破坏,其中2例位于胸壁,1例位于肩胛骨;5例为溶骨性骨质破坏,其中2例位于后纵隔、1例发生于副鼻窦、1例发生在腰椎和1例发生在骶椎。3例为未伴骨破坏的软组织肿块,其中2例发生于腹膜后,1例发生于皮下脂肪层内。除发生在皮下脂肪层内病灶较小者,其余病灶都较大,平均直径为8 cm。软组织肿块以压迫推移邻近组织的方式生长。瘤体内钙化少见。结论 pPNET的MSCT典型表现为巨大软组织肿块,伴或不伴骨质破坏,增强呈均匀或非均匀的团絮状强化,大血管穿行于瘤体内较少见。有一定的特点,需与其他恶性软组织肿瘤鉴别。MSCT能较好显示病变内部结构,血供状况以及与邻近组织的关系,有助于术前分期、手术方案的确定、有无远处转移和治疗效果评价。

MSCT Diagnosis of Peripheral Primitive Neuroectodermal Tumors

Objective To analyze the MSCT appearances of peripheral primitive neuroectodermal tumors(pPNETs)and to improve its recognition.Methods MSCT findings of 11 patients with pPNETs confirmed by pathology were reviewed retrospectively.Results The CT findings of 8 cases were large soft tissue mass combined with bony destruction,3 cases of them presented as radiation like periosteum reaction and local bony destruction,2 cases were located in chest wall and 1 case was located in scapular.In other 5 cases with osteolytic destruction,2 of them were located in posterior mediastinum,1 in nasal sinus,1 in lumber vertebra and another one was in pelvic.3 cases were soft tissue mass without bony destruction,2 of them were located in retro peritoneum and 1 was located in subcutaneous fat.Except the mass in subcutaneous fat was small,others were large,their average diameter was 8cm,which displaced adjacent soft tissue structures.Calicification was also rare feature.Conclusion The typical findings of pPNET are large soft tissue mass with or without bony destruction,the lesions appear as moderate inhomogeneous enhancement.MSCT can show the intratumor structures and the extent of the tumor very well,which is helpful in detecting distant metastases and evaluating the response to treatment.