大肠"高危腺瘤"的临床意义

目的：研究大肠“高危腺瘤“的构成,肠段分布及高危因素的特点,以有助于腺瘤癌变的早期防治。方法：经大肠镜检发现大肠腺瘤患者258例,详细记录腺瘤部位、大小、形态、并送活检。有下述三项高危因素之一腺瘤为“高危腺瘤”包括：腺瘤大于20mm绒电状腺瘤;伴有中、重度异型增生的腺瘤。大部分腺瘤经高频电切术切除并送全瘤病理。有5l例患者行潜血检测。结果：258例患者共检出腺瘤308枚,其中“高危腺瘤”132枚。具有上述单项、双项及三项高危险因素素腺瘤数分别23、99、10枚,各占“高危腺瘤”总数的17．4％,75．0％,7、6％。“高危腺瘤”数分布以立肠、乙状结肠为最多(占72％),自运段向近段递减。其中同时具有三项高危险因素的10枚腺瘤的分布为立肠4枚,乙状结肠3枚,降结肠3枚。5l例便潜血检测可见“高危腺瘤”显性血便及便港血阳性率均明显高于非“高危腺瘤”(P＜0．05)。结论：“高危腺瘤”指有高度恶变倾向的腺瘤,其构成包括：腺瘤大于20mm,绒毛状腺瘤,件有中、重度异型增生的腺瘤。具有多项危险因素的腺瘤可能具有更强的恶变趋向性;“高危腺瘤”经内镜切除后复发出现“高危腺瘤”或癌变的机率显著高于原先无高危因素者,说明“高危腺瘤”摘除术后随诊甚为重要：“高危腺瘤”的分布存在着明显的区域性集中的特征,以直肠、乙状结肠为主,因此这段的内镜取材尤为重要;便潜血检查在“高危腺瘤”阳性率高,可能具有更简便和有效的早期发现癌变的特点。

CLINICAL SIGNIFICANCE OF COLORECTAL "HIGH RISK ADENOMAS"

Objective:To determine the formation and distribution of colorectal "high risk adenomas" and the characteristics of high risk factors.Methods:We detected 258 patients by with colonoscopy .The size, location and pattern were recorded when adnomas were found .All adenomas were examined by experienced pathologists,using the WHO classification."High risk adenomas"included those that were larger than 20mm in diameter,those containing villous structures ,and adenomas with moderate and severe dysplasia.Fecal occult blood tests were measured on 51 patients.Results:We found 308 adenomas in 258 patients .In all ,132 adenomas were "high risk adenomas".The percentage of "high risk adenomas" containing one ,two and three high risk factors were 17.4%,75.0%,7.6% respectively.Ninety-six(72%)"high risk adenomas" were located in rectosigmoid colon.The percentage of "high risk adenomas" with positive fecal occult blood was higher than that of no "high risk adenomas".( P< 0.05).Conclusion:Adenomas of particularly high risk of malignatnt transformation are termed "high risk adenomas".They include those that were larger than 20mm in diameter,those comtaining villous structures,and adenomas with moderate and severe dysplasia."High risk adenomas"containing fewer high risk factors may be liable to carcinogenesis .The incidence of recurrent "high risk adenomas"or carcinogenesis in patients whose "high risk adenomas" had been cut under colonoscopy may be higher than that of no "high risk adenomas" previously."High risk adenomas" are mainly located in rectosigmoid colon.So it is important to emphasize the biopsy in rectosigmoid colon.The positive fecal occult blood is higher in patients with "high risk adenomas" ,which indicates that fecal occult blood test may be an easier and more effective method to detect colorectatl neoplasms early.