Zhou Jian-jun, Wang Jian-hua, Zeng Meng-su, Yan Fu-hua, Zhou Kang-rong, Ding Jian-guo
Department of Diagnostic Radiology, Zhongshan Hospital, Fudan University, Shanghai, China.
Zhonghua Zhong Liu Za Zhi. 2009 Sep;31(9):697-700.
To investigate the CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs) and evaluate its diagnostic value.
The clinicopathological data of 9 surgically treated patients with peripheral primitive neuroectodermal tumors confirmed by pathology were collected, spiral CT (4/9) and MRI (6/9) plain scanning and dynamic enhancement scanning were performed preoperatively. Both CT and MRI scannings were performed in 1 case. Those CT and MR images were retrospectively reviewed and analyzed together with clinicopathological findings.
The 9 lesions were located in skeletal muscles (n = 6), pelvic cavity (n = 2) and thoracic cavity (n = 1). The tumor size was 7.4-18.3 cm in diameter with a mean diameter of 11.6 cm. The shape of those lesions was round or ellipse (4 lesions) and irregular (5 lesions). The tumor usually presented as ill-defined masses, with homogeneous (n = 2) or inhomogeneous density (n = 7). Seven cases, including the 3 lesions located in the chest and pelvis, showed obvious necrosis and multilocular cyst formation. The tumors showed iso-density as that of the adjacent muscles on CT plain scans and moderate heterogeneous enhancement after intravenous injection of contrast agents. The features of the tumors on the MRI including slightly low signal intensity on SE T1-weighted imaging, iso-signal intensity or slightly high signal intensity on FSE T2-weighted imaging and heterogeneous dynamic delayed contrast-enhancement with obvious necrosis in most of them. Six cases had a lesion in the skeletal muscles, presented as a giant ill-defined masse surrounding bone and extended along neural route with bone destruction to varying degrees.
Primitive neuroectodermal tumor is a kind of malignant tumor with proliferation of small, undifferentiated neuroectodermal cells, usually occurring in children or adolescent and frequently located in the extremities, chest cavity, pelvic cavity and chest wall. It typically presents as a large, ill-defined masse extending along neural route with heterogeneous and obvious enhancement after intravenous injection of contrast agents. The tumors located in the chest and pelvic cavities and some in the extremities show obvious necrosis and multilocular cyst formation, while some of the tumors in the extremities appear as homogeneous solid masses.
探讨外周原始神经外胚层肿瘤（pPNETs）的CT及MRI表现，并评估其诊断价值。
收集9例经手术治疗且病理确诊的外周原始神经外胚层肿瘤患者的临床病理资料，其中4例术前行螺旋CT平扫及动态增强扫描，6例术前行MRI平扫及动态增强扫描，1例同时行CT和MRI扫描。对这些CT及MR图像进行回顾性分析，并结合临床病理结果。
9个病灶分别位于骨骼肌（6例）、盆腔（2例）和胸腔（1例）。肿瘤直径7.4 - 18.3 cm，平均直径11.6 cm。病灶形态为圆形或椭圆形（4个）及不规则形（5个）。肿瘤多表现为边界不清的肿块，密度均匀（2例）或不均匀（7例）。7例，包括位于胸部和盆腔的3个病灶，可见明显坏死及多房性囊肿形成。CT平扫肿瘤与相邻肌肉呈等密度，静脉注射对比剂后呈中度不均匀强化。MRI表现为SE T1加权像呈稍低信号，FSE T2加权像呈等信号或稍高信号，动态延迟对比增强不均匀，多数有明显坏死。6例骨骼肌病灶表现为边界不清的巨大肿块，包绕骨骼并沿神经走行扩展，伴有不同程度的骨质破坏。
原始神经外胚层肿瘤是一种由未分化的小神经外胚层细胞增殖形成的恶性肿瘤，多见于儿童或青少年，好发于四肢、胸腔、盆腔及胸壁。典型表现为边界不清的较大肿块，沿神经走行扩展，静脉注射对比剂后强化不均匀且明显。位于胸部和盆腔以及部分四肢的肿瘤可见明显坏死及多房性囊肿形成，而部分四肢肿瘤表现为均匀实性肿块。
