Investigation of endoluminal ultrasonographic characteristics of rectal adenocarcinoma and rectal mucous adenocarcinoma.

Abstract

Objective To investigate the endoluminal ultrasonographie characteristics of adenoearcinoma and mucous adenocareinoma of the rectum. Methods The ultrasonographie characteristics of thirty eases of advanced adenoeareinoma of the rectum and twenty-eight eases of rectal mucous adenoearcinoma were analyzed retrospectively in comparison with their eorresponding pathologic images. Results In advanced adenocareinoma of the rectum, 28 eases manifested rough endoluminal surface, of which 19 marked by thickened changes without arrangement of layers, 10 had indistinct arrangement of layers in some areas and one had clear arrangement of layers. In the deepest margin of infiltration, 17 eases manifested sentus, homed or knot-like protuberance, while 5 marked by wavy margins, and 8 cases had clear and fiat margins. In 25 eases of rectal mucous adenocareinoma, 20 manifested smooth endoluminal surface. With regard to infiltration of tumors to rectal wall, 6 cases manifested clear arrangement of layers, while 13 had clear arrangement of layers in part and 6 had no clear arrangement. In the deepest part of infiltration, 8 eases manifested slippery and fiat margins and 10 manifested wavy margins and 7 had a few sentus, homed or knot-like protuberance locally. According to ultrasonic results of the depth of infiltration to rectal wall in comparison with pathologic findings, 25 eases were diagnosed accurately, while in two cases the diagnosis was too shallow and in three eases it was too deep. In rectal mucous adenocarcinoma, 10 cases got correct diagnosis and 14 were diagnosed superficially and one got too deep. The accuracy of ultrasonic diagnosis on rectal mueoas adenoearcinoma was apparently lower than that of adenoeareinoma and most of the misdiagnosis were too superfieiai. Conclusion There are different ultrasonographie characteristics of rectal adenoeareinoma and rectal mucous adenoeareinoma, which can be helpful for the typing of rectal carcinoma and avoiding excessively superficial misdiagnosis. Key words: Rectal neoplasms; Endosonography