中村 雅美¹, 大西 さゆり¹, 雪本 幸美¹, 中村 芳久², 辻 悦生², 菅野 亮³, 北原 義介³, 河崎 正³, 平石 久美子⁴, 下村 知雄⁵, 中井 健裕⁵, 中井 博章⁵, 鈴木 淑男⁵, 磯田 幸太郎⁶

Masami NAKAMURA¹, Sayuri OONISHI¹, Satimi YUKIMOTO¹, Yoshihisa NAKAMURA², Etsuo TSUJI², Makoto SUGANO³, Yoshisuke KITAHARA³, Tadashi KAWASAKI³, Kumiko HIRAISHI⁴, Tomoo SHIMOMURA⁵, Takehiro NAKAI⁵, Hiroaki NAKAI⁵, Yoshio SUZUKI⁵, Koutarou ISODA⁶

¹河﨑内科病院超音波検査室, ²河﨑内科病院放射線検査室, ³河﨑内科病院内科, ⁴りんくう総合医療センター放射線科, ⁵国立療養所千石荘病院外科, ⁶南大阪病院病理

¹Department of Ultrasonographic Laboratory, Kawasaki Naika Hospital, ²Department of Radiographic Laboratory, Kawasaki Naika Hospital, ³Department of Internal Medicine, Kawasaki Naika Hospital, ⁴Department of Radiology, Rinku General Medical Center, ⁵Department of Surgery, National Sanitarium Sengokusou Hospital, ⁶Department of Pathology, Minami Osaka Hospital

キーワード : color Doppler ultrasonography, gastrointestinal stromal tumor, immunohistochemical stain, strangulated ileus, tornado sign

A 53-year-old woman was hospitalized by ambulance because of vomiting and severe abdominal pain. Physical examination disclosed tenderness on the periumbilical region, slight abdominal fullness, and a diminished bowel sound, but without muscular defense or ascites. An abdominal enhanced CT scan showed a thickening of the wall of the small intestine, dilatation of the lumen, and a slightly contrasting lobulated mass over the urinary bladder. These signs suggested a disturbance in circulation caused by a twist in the stalk of the polypoid mass. The ultrasonography showed a keyboard-like sign in the dilated lumen of the small intestine and a remarkably large mass of about 12 cm in maximum diameter on the lower abdominal region with a clear margin and heterogenous internal echogenicity. Color and power Doppler ultrasonographic study of the mass showed few color-flow signals but detected feeding-vessels connected to the intestinal vessels in the upper part of the mass. An obstruction was detected in the small intestine, a screw sign on gray-scale ultrasonography and a tornado-like vessel image on color Doppler ultrasonography. Clinical diagnosis was a strangulated ileus complicated by a twisted stalk of the polypoid mass in the small intestine. On surgery, the mass was found to originate orally 140 cm from the ileocecal junction; it measured 12×7×5 cm and had an extraluminal stalk on the opposite side of the mesenterium. Pathologic findings included a gastrointestinal stromal tumor, a so-called GIST, originating in the ileum. The microscopic findings included tightly arranged pleomorphic spindleshaped cells, and 11 mitotic figures were seen in 20 high-power fields on hematoxylin-eosin staining. Immunohistochemically stained the specimens reacted positively to CD 34, c-kit, and HHF 35, but negatively to vimentin, Desmin, and S-100 protein. Our diagnosis of malignant GIST associated with myogenic differentiation was based on this evidence. Color Doppler ultrasonography was useful for the detection of disturbed circulation caused by a twisted stalk.