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15例腹膜后神经鞘瘤患者均为单发病灶，12例位于腹部腹膜后，均位于脊柱旁区，其中10例位于脊柱与肾脏之间，腰大肌前方；3例位于盆部腹膜后，其中2例位于骶前间隙，骶孔前方，另1例位于右侧坐骨神经走行区。超声显示腹膜后神经鞘瘤为实性3个，囊实性9个，囊性3个。本组多数腹膜后神经鞘瘤的超声表现为：形态规则（86.7%）、边界清晰（93.3%）、内部囊性变（80%）、血流信号不丰富（66.7%），未显示钙化（86.7%）、靶征（93.3%）及受累神经（93.3%）。相较于浅表神经鞘瘤，腹膜后神经鞘瘤的肿瘤体积更大，更常见内部囊性变、血流信号不丰富；更少见靶征及受累神经（P＜0.05）。腹膜后神经鞘瘤有着不同于浅表神经鞘瘤的超声特征。

All 15 cases of retroperitoneal schwannoma were solitary, 12 cases were located in the paraspinal area of abdominal retroperitoneum, of which 10 cases were located between the spinal column and kidney, in front of psoas major muscle, 3 cases were located in the pelvic retroperitoneum, of which 2 cases were located in the anterior sacral space, and the other case was located in the area of right sciatic nerve. Ultrasonography showed there were 3 schwannomas displaying as solid tumors, 9 as cystic and solid ones, and 3 as cystic ones. Ultrasonic features of most retroperitoneal schwannomas in this study were as follows: regular morphology (86.7%), clear boundary (93.3%), internal cystic degeneration (80%), poor blood flow signal (66.7%), no calcification (86.7%), no target sign (93.3%) and no detected affected nerve (93.3%). Compared with superficial schwannoma, retroperitoneal schwannomas have larger tumor volume, more common internal cystic degeneration and poor blood flow signal, but target signs and affected nerves were less common (P<0.05). Retroperitoneal schwannomas have different ultrasonic features from superficial schwannomas.