不同病理类型结直肠息肉的差别

目的 根据不同病理类型息肉的临床特点，找出不同息肉之间的差别，为临床诊断提供依据。方法 回顾4年820例结直肠息肉病例，分析患者年龄；息肉的部位、数目、大小、形态、病理类型、不典型增生程度和癌变情况。结果 ①腺瘤性息肉：包括管状、混合状、绒毛状三种息肉，其变化规律为平均体积逐渐增大、分叶和黏膜改变逐渐多见、不典型增生和癌变率亦逐渐增高。②幼年性息肉：发病年龄一般较小，直肠多见，平均体积大，多带蒂，分叶少见。③炎性息肉：平均体积小，多无蒂、光滑和不分叶。结论 各型息肉内镜下具有一定特征，可以做为初步判定息肉性质的参考依据。     

结直肠侧向发育型肿瘤并发结直肠息肉的预测因子及发生恶变的危险因素

目的探究结直肠侧向发育型肿瘤(colorectal laterally spreading tumors, CLST)并发结直肠息肉的独立预测因子及CLST合并结直肠息肉发生恶变的独立危险因素。方法回顾性收集2016年1月—2021年12月在大连医科大学附属第二医院行内镜检查发现CLST, 并接受内镜下治疗的260例患者的临床资料。根据是否与结直肠息肉共存将CLST患者分为共存组(n=135)与非共存组(n=125), 比较两组的临床病理特征差异, 采用二元Logistic回归分析共存现象的预测因子。根据共存组CLST的浸润深度, 将共存组分为共存恶性组(n=38)与共存非恶性组(n=97), 采用二元Logistic回归分析CLST合并结直肠息肉发生恶性变的危险因素。结果男性(P=0.002, OR=2.355, 95%CI:1.354～4.099)、绒毛管状腺瘤(P=0.022, OR=3.873, 95%CI:1.214～12.355)、既往有息肉病史(P=0.001, OR=2.738, 95%CI:1.527～4.909)是CLST合并结直肠息肉的独立危险因素。该预测模型受试...     

Small colorectal polyps

The histology of small (≤0.5 cm.) colorectal polyps removed during total colonoscopy in 303 patients was reviewed to determine their clinical significance. There were 178 male patients and 125 females, with a median age of 64 years (range, 26 to 97 years). A total of 766 polyps were treated, 60 percent being adenomatous and 22 percent hyperplastic. Hyperplastic polyps were more common in the rectum (71 percent) while adenomas were more common in the colon (63 percent). Hyperplastic polyps in the colon were associated with adenomas in 75 percent of cases and hyperplastic rectal polyps were associated with proximal adenomas in 63 percent. There were six mixed hyperplastic/adenomatous polyps. Of the 458 adenomas, 449 were tubular, eight were tubulovillous, and one was villous. Moderate dysplasia was noted in 23 (5 percent) and severe dysplasia in four (0.9 percent). There were associated large adenomas in 84 patients. Small colonic polyps are usually adenomatous and should be destroyed. Biopsy may be important if no other neoplasm has been identified. Small rectal polyps are usually hyperplastic but may be associated with proximal adenomas. Because of the uncertain significance of hyperplastic polyps they should also be treated, and are a relative indication for total colonoscopy. Read at the meeting of the American Society of Colon and Rectal Surgeons, Washington, D.C., April 5 to 10, 1987.     

Malignant colorectal polyps

Nowadays, the number of cases in which malignant colorectal polyps are removed is increasing due to colorectal cancer screening programmes. Cancerous polyps are classified into non-invasive high grade neoplasia (NHGN), when the cancer has not reached the muscularis mucosa, and malignant polyps, classed as T1, when they have invaded the submucosa. NHGN is considered cured with polypectomy, while the prognosis for malignant polyps depends on various morphological and histological factors. The prognostic facto...     

Malignant colorectal polyps

Opinion Statement  

Genetics of colorectal polyps

Currently, genetic investigation of human tumours starts from the analysis of advanced cancers. Once a given genetic alteration has been found in advanced tumours, this same alteration is investigated in the pre-neoplastic lesions. The aim of this approach is to assess the significance of the genetic alteration during the carcinogenic process. This review is focused on alterations that have proven to be present in pre-neoplastic lesions that are associated to colorectal cancer (ACF and early adenoma). Alterations that are present at the early stages are likely to play a crucial role in colorectal tumorigenesis. Colorectal tumorigenesis is extremely heterogeneous from a genetic point of view: tumours follow alternative molecular pathways and show different phenotypes (CIN, MIN and CIMP). Tumours are genetically heterogeneous from their early stages: the sequence of genetic events that accumulate within cells during progression to malignancy appears to be determined by the first events. These events have been investigated in ACF and in early adenomas. The understanding of the molecular mechanisms underlying genesis and progression of colorectal tumours will allow the development of new tools for cancer prevention and early diagnosis, as well as for therapeutic approaches specific for different molecular targets.     

Epidemiology of colorectal polyps

The prevalence of colorectal adenomatous polyps varies widely from country to country. Among asymptomatic, average-risk patients, adenoma prevalence averages approximately 10% in sigmoidoscopy studies and more than 25% in colonoscopy studies, whereas the prevalence of colorectal cancer among these patients is less than 1%. These data may change in the future due to the advent of new technological approaches and, in particular, chromo- and magnifying endoscopy as well as confocal laser endoscopy. The cumulative incidence of new adenomas within 3 years after normal endoscopy averages about 7% by flexible sigmoidoscopy and 27% by colonoscopy. As far as risk factors for colorectal adenomas are concerned, several data are now available on the potential role of various diet items. Tobacco smoking may be important in the early stages of adenoma formation, but not necessarily in the later stages. Alcohol consumption elevates the risk of adenomatous colorectal polyps and this seems increased by ADH3 polymorphism. Another gene-environment relationship of interest in colorectal tumorigenesis may be based on folate's effects on K-ras mutations.     

Micronucleus analysis in patients with colorectal adenocarcinoma and colorectal polyps

AIM： To determine, by counting micronucleus （MN） frequencies, whether chromosomal or DNA damage have an effect on the pathogenesis of early colorectal adenocarcinoma （CRC）. METHODS： We analyzed MN frequencies in 21 patients with CRC, 24 patients with colon polyps [10 neoplastic polyps （NP） and 14 non-neoplastic polyps （NNP）] and 20 normal controls. RESULTS： MN frequency was significantly increased in CRC patients and in NP patients compared with controls （3.72 ± 1.34, 3.58± 1.21 vs 1.97 ± 0.81, P 〈 0.001）. However, there was no difference in the MN frequency between CRC patients and NP patients （P 〉 0.05）. Similarly, there was no difference in the MN frequency between NNP patients （2.06 ±0.85） and controls （P 〉 0.05）. CONCLUSION： Our results suggest increased chromosome/DNA instabilities may be associated with the pathogenesis of early CRC.     

Prevalence of colorectal polyps in Filipinos

From May 1988 to May 1990, a prospective autopsy study was performed in patients who died at the Philippine General Hospital in Manila, Philippines. Patients younger than 10 years of age, patients with a history of large bowel resection, and patients whose deaths were related to trauma were excluded. There were 416 patients; 246 were males, and 170 were females. The mean age was 47 years (range, 11–95 years). Six of the 416 patients (1.4 percent) were found to have polyps. One patient had an inflammatory polyp, one was diagnosed with familial adenomatous polyposis, and one had an associated cecal carcinoma. Five sporadic adenomatous polyps were found in the remaining three patients (prevalence rate, 0.7 percent). All of the adenomatous polyps were located distal to the hepatic flexure and exhibited only mild atypia. The mean size was 6.4 mm (range, 2–20 mm). The incidence of colorectal adenomas in Filipinos is low compared with that in age-adjusted Western populations. This finding coincides with a low incidence of colorectal carcinoma. The documentation of a low risk for adenomatous polyps and colorectal cancer indicates that it would be difficult for massive screening programs to demonstrate a significant positive impact on the early detection of colorectal neoplasias in the Filipino general population.Supported in part by an educational grant from IVONYX.     

Physician accuracy in diagnosing colorectal polyps

Since the medical management of persons with adenomatous colorectal polyps differs from that of those with hyperplastic polyps, accuracy of diagnosis is essential. Although many physicians have grown confident that their skills of visual diagnosis are adequate, few data exist to support this confidence. In order to examine the accuracy of physicians' judgments regarding colorectal polyp histology, the visual diagnosis of physicians experienced in endoscopy was compared with the histologic report. Eighty-one polyps were discovered by flexible sigmoidoscopy among 718 participants in a colon cancer screening program. Eighty percent of all polyps were detected accurately. The diagnostic sensitivity of detecting adenomas was 69 percent, while specificity (accurate diagnosis of hyperplastic polyps) was 86 percent, and there were an additional eight false negative and eight false positive diagnoses. Further analyses revealed that there are individual patterns of diagnostic mistakes made by physicians and that mistakes frequently are related to polyp size. These findings are particularly important in light of the expanding numbers of relatively inexperienced primary care providers performing flexible sigmoidoscopy whose diagnoses may be strongly dependent on polyp size. This research was done through, and supported by, the Center for Occupational Health, Department of Family Medicine, Wayne State University, Detroit, Michigan.     

Emerging concepts in colorectal serrated polyps

Colorectal serrated polyps are heterogeneous epithelial lesions characterized by a serrated architecture. They include the classical hyperplastic polyps and the much rarer serrated adenomas and mixed polyps. Whereas serrated adenomas are composed of an unequivocal adenomatous epithelium with architectural serrated, mixed polyps include two separate hyperplastic and adenomatous components. During the past few years, another type of serrated polyp with only very subtle proliferation abnormalities has been described. These atypical serrated polyps may occur either sporadically or in the context of colorectal polyposis. Despite their close resemblance to traditional hyperplastic polyps, some authors argued that they should be regarded as authentically neoplastic lesions and have proposed to call them "sessile serrated adenomas". Their malignant potential requires their removal when discovered during colonoscopy. This article reviews the histological features, the endoscopic appearance, the natural history and the molecular phenotype of the different categories of serrated polyps and introduces the concept of "serrated neoplastic pathway" in the development of colorectal cancer.     

Gender differences in gastroenterology

Balancing professional and personal life can be particularly challenging for young women at the prime of their reproductive years. Young female gastroenterologists were found to work for larger groups, take fewer calls, and receive less compensation than their male counterparts. Getting more women into gastroenterology will be an achievable goal if the needs of female trainees are understood and met.     

Gender differences in arrhythmias

Electrocardiographic and electrophysiologic differences between men and women have long been noted. Women have a higher intrinsic heart rate than men, along with a longer corrected QT interval and a shorter sinus nodal recovery time. The incidence of and risk factors for a variety of arrhythmias differ between men and women. Atrioventricular nodal reentry tachycardia has a 2:1 female-to-male predominance, while accessory pathways are twice as frequent in men. Although atrial fibrillation is more prevalent in men of all age groups, the absolute numbers of men and women with atrial fibrillation are equal, and the associated morbidity and mortality experienced by women with atrial fibrillation appear to be worse. Women have a lower incidence of sudden cardiac death, and female survivors of sudden cardiac death have a lower frequency of spontaneous or inducible ventricular tachycardia. On the other hand, drug-induced torsade de pointes and symptomatic long QT syndrome have a female predominance. Therefore, greater caution should be used when prescribing QT-prolonging drugs in women. The incidence of arrhythmias is increased during pregnancy, and management of pregnant patients poses a significant challenge. The mechanisms of these gender differences are unclear but may be related to hormonal effects and the shorter QT interval in adult males. Pharmacologic and nonpharmacologic therapies are usually equally efficacious, but the risks of pharmacologic therapy are different in men and women. Atrial fibrillation may be more difficult to treat in women.     

Gender differences in psychopharmacology

At least half of all patients with psychiatric disorders are female. Depressive disorders occur twice as often in women than in men. Despite the need for a gender-specific approach in treating psychiatric disorders, little is known about gender issues in psychopharmacology. It has been recognized that women respond better than men to serotonin-modulating substances but that this effect is reversed after menopause. Furthermore, women develop gynecological complications under medication with certain psychopharmacological agents which calls the use of these drugs into question. Side effects such as weight gain, hyperglycemia, cardiac arrhythmias, and sexual dysfunction also occur more frequently in women than in men. Pregnancy is a particularly sensitive aspect. The risk that a mother with a psychiatric disorder could relapse if the drug is discontinued has to be weighed against the risk of the child being born with an anomaly or developing prenatal complications.