罕见直肠肛管恶性肿瘤的临床与影像学诊断

【目的】探讨罕见直肠肛管恶性肿瘤的临床影像学表现。【方法】报道罕见直肠肛管恶性肿瘤15例．包括非何杰金氏淋巴瘤3例．平滑肌肉瘤9例，脂肪肉瘤2例，恶性黑色素瘤1例．15例中12例做了CT检查，9例进行了气钡灌肠检查。【结果】气钡灌肠示该类肿瘤主要表现为直肠下端或肛管隆起性病变．肠腔明显狭窄．可伴不规则龛影．肉瘤常较大．而恶性淋巴瘤常表现多发。CT表现为直肠或肛管肠壁增厚或局部肿块，肉瘤肿块常较大，多伴更低密度坏死区。邻近组织或器官可受累及。【结论】罕见直肠与肛管恶性肿瘤常用影像学检查方法为气钡灌肠与CT．其表现仅具有相对性特征。

Rare Malignant Tumors of Rectum and Anal Canal :Clinical and Imaging diagnosis of 15 Cases

Objective]To investigate the clinical features and imaging appearances of rare malignant tumors of rectum and anal canal.Methods]Fifteen cases of rare malignant tumors of rectum and anal canal,including three cases of non-Hodgkin's lymphomas,nine of leiomyosarcomas,two of liposarcomas and one of malignant melanomas,were reported in this study.Twelve of them were examined by computed tomography(CT) and nine by double-contrast irrigoradioscopy.Results]These rare malignant tumors were detected on irrigoradioscopy as protrusion lesions or luminal stenosis of inferior segmental rectum or anal canal,usually associated with irregular niches.CT demonstrated them as thickening of the wall or localized masses of rectum or anal canal.Sarcomas usually appeared as biggish masses associated with area of necrosis and invaded adjacent tissues or organs;whereas malignant lymphomas were often demonstrated as multiple lesions.Conclusion]Irrigoradioscopy and CT are routine imaging examination for rare malignant tumors of rectum and anal canal,but can only provide relative characteristics about them.