CT and MRI imaging features of peripheral primitive neuroectodermal tumors / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the CT and MRI features of peripheral primitive neuroectodermal tumors (pPNETs) and evaluate its diagnostic value.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Value of spiral CT in diagnosis of cystic renal cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the image features and the diagnostic value of spiral CT for cystic renal cell carcinoma.</p><p><b>METHODS</b>The clinical data and CT manifestations of 17 operated and pathologically proven cystic renal cell carcinoma were retrospectively analyzed. There were 12 males and 5 females with an average age of 47.3 years (33 - 82 years). Plain and contrast CT scan (Siemens somatom) single layer sensation 16 layer spiral CT had been performed before operation. The image of artery phase (30 - 40 s), venous (60 - 70 s) and excretory (120 - 180 s) were respectively obtained after contrast administration. Various image reconstructions were done using Siemens Wizard workstation based on the raw images.</p><p><b>RESULTS</b>It was found that 5 cystic renal cell cancers located in the right kidney and 12 in the left kidney. The long dimension of the tumor arranged from 21 - 100 mm with an average of 57 mm. The tumor looked like a round or round-like shape with density similar to fluid on plain CT scan. Some cystic renal carcinomas had a thick wall. Some had single or multiple cystic spaces filled with fluid of different densities. Some had infiltrated out of kidney surface or into renal sinus. Some showed enhanced nodules on the wall.</p><p><b>CONCLUSION</b>Cystic renal cell carcinoma has its own specific morphologic features in spiral CT scan. Spiral CT may be very helpful in the diagnosis of cystic renal cell carcinoma before operation.</p>