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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clarification of the ultrastructural features of the three different grades of histologic atypia of adenomas (i.e., mild, moderate, and severe atypia) with reference to carcinoma of the human colon and rectum was undertaken using electron microscopic quantitative analysis. Ten normal epithelia, 36 adenomas (14 with mild atypia, 13 with moderate atypia, and 9 with severe atypia) and 14 carcinomas (well-differentiated adenocarcinoma) were examined with light and electron microscopes. Although it has been generally accepted that malignant transformation of an adenoma gradually proceeds with increasing atypia, using light microscopy, ultrastructural quantitative analysis clearly revealed that fine features of individual atypia did not correspond with histologic grades of atypia. Ultrastructural changes occurred abruptly in moderate atypia and showed similar cellular characteristics to carcinoma cells. Mild atypia was almost similar in appearance to normal epithelial cells. Striking changes in the moderate atypic cells were plane apposition of the cell membrane, decrease of the desmosomes, and increase of the lysosomes. These atypical cells were assumed to play a significant role in the adenoma-carcinoma sequence. Therefore, radical surgical therapy would be required for moderate atypic adenoma of the large bowel that is difficult to remove endoscopically.
Dis Colon Rectum 1989 Jan
PMID:Quantitative electron microscopic study on grades of atypia in adenomas of the human large bowel. 291 Jun 61

Seventy-five colorectal carcinoma patients (100 separate cancers) with verified cancer family syndrome were re-examined for the evaluation of histologic characteristics in carcinomas and adenomatous polyps in this inherited syndrome in a comparison with control patients with colorectal carcinoma but no hereditary background. In the cancer family syndrome group there were significantly more mucinous carcinomas (35 to 39 percent vs. 20 percent; P less than 0.05-0.01), and also more poorly differentiated tumors (24 vs. 12 percent) than in the control group. The differences could not be explained by the site or stage of the tumors or by the age or sex of the patients. Additional adenomas occurred quite often both in cancer family syndrome patients (19 percent) and in the controls (16 percent). In the cancer family syndrome group, however, there were more adenomas with moderate or severe dysplasia (P less than 0.01) and more adenomas with villous features (P less than 0.05) than in the control group. Mucinous histologic features in colorectal carcinoma, although not fully specific, might be characteristic of cancer family syndrome, and thus serve as one sign in the identification of the syndrome. The presence of the adenoma-carcinoma sequence in cancer family syndrome also was supported, and the histologic aggressivity of the associated adenomas might signify an accelerated advancement of this phenomenon in cancer family syndrome.
Dis Colon Rectum 1986 Dec
PMID:Histopathology of colorectal carcinomas and adenomas in cancer family syndrome. 302 33

A case control study of 150 individuals with colonic symptoms and diverticular disease diagnosed by total colonoscopy was performed to ascertain whether adenomas and carcinomas are detected with a higher frequency in these patients than in matched controls with symptoms but not diverticular disease. Adenomas and carcinomas were seen in 36 percent of the patients and in 17 percent of the controls (P less than .001); the overall odds ratio was calculated to be 3.0 (95 percent confidence interval +/- 1.8). When examined separately, adenomas maintained their significantly higher frequency (27 vs. 10 percent, P less than .001), while no difference was observed as regards carcinomas (9 vs. 7 percent). The odds ratios for adenomas and carcinomas were calculated to be 3.5 +/- 2.5 and 1.4 +/- 1.4, respectively. From the fifth to eighth decades there was a fourfold increase in premalignant and malignant lesions in the patient group and a twofold increase in controls. With relation to sex, a statistically significant difference was reached in men but not in women in the sample examined. These data show that symptomatic patients with colonic diverticula have more frequent adenomas, but not carcinomas, than symptomatic control matched by sex and age.
Dis Colon Rectum 1988 Oct
PMID:Association of colonic diverticula with adenomas and carcinomas. A colonoscopic experience. 271 38

The cellular distribution of the carbohydrates labeled by Dolichos bifluorus agglutinin (DBA), peanut agglutinin (PNA), and wheat germ agglutinin (WGA) were studied in 21 normal colonic mucosae, 17 transitional mucosae, 9 nonneoplastic polyps (NNP), 27 adenomas, and 25 colorectal carcinomas. In normal mucosa DBA bound selectively to mucin of the goblet cells in the upper colonic crypt and to apical cytoplasm of the superficial columnar cells with a strong linear pattern. PNA binding was present only in the supranuclear portion (Golgi area) of the cells. WGA showed a strong reactivity in the goblet-cell mucin and in the supranuclear portion and apical cytoplasm of columnar cells. Transitional mucosa (TM) showed a decrease in DBA binding to goblet-cell mucin, which was replaced by an increase in PNA reactivity. The DBA linear pattern in the apical cytoplasm of columnar cells was unmodified, however. Changes similar to those of TM were observed in juvenile and Peutz-Jeghers polyps. Adenomas showed a progressive loss of DBA reactivity and an increase in PNA positivity related to the degree of dysplasia. This change was more evident in the linear pattern of apical cytoplasm. Only 32% of the carcinomas reacted with DBA and those were mucinous and well-differentiated adenocarcinomas. WGA was positive in all carcinomas with a different pattern than in normal mucosa. These findings suggest that the different lectin-binding patterns in normal and neoplastic colonic mucosa are related to the degree of cellular differentiation. In the process of malignant transformation the carbohydrate distribution undergoes progressive changes through the adenoma-carcinoma sequence. These changes are related to the degree of dysplasia in adenomas and to the degree of differentiation in carcinomas.
Dis Colon Rectum 1988 Nov
PMID:Lectin binding patterns in normal and neoplastic colonic mucosa. A study of Dolichos biflorus agglutinin, peanut agglutinin, and wheat germ agglutinin. 318 Sep 62

Colonoscopic biopsies from 32 patients were studied at the ultrastructural level using a scanning electron microscope (SEM). Sixteen of the 32 patients had a previous diagnosis of total ulcerative colitis (UCR greater than 10 years) in protracted remission. The colonic mucosa was normal at endoscopic and histologic examinations (UCRN). The remaining 16 patients had normal colonic mucosa, but had an adenoma or an adenocarcinoma elsewhere in the colon. Several ultrastructural parameters were investigated, such as the number of crypts per area, the distance between the crypts, the outline of mucosal units, the number of mucous cells, the outline of absorptive cells, and the number of villi per area. Quantitative determinations of SEM structures (including measurements with an interactive digital image analyzer system; MOP 30, Zeiss Contron) were made. The results showed no significant differences between the various parameters (except for the number of crypts per area) between patients with UCRN and controls. The possibility of a total (or quasi-total) restitutio ad integrum of the colonic mucosa in certain patients with UCR is discussed. An international policy regarding the colonoscopic surveillance of patients with UCRN should be elaborated. It is suggested that the time interval between control colonoscopic biopsies in patients with UCRN should be increased substantially.
Dis Colon Rectum 1988 Dec
PMID:Ulcerative colitis in protracted remission. A quantitative scanning electron microscopic study. 321 98

Patients with a personal history of rectal cancer are considered at high risk for metachronous large-bowel primaries. Since a malignant growth was the main reason for performing a colostomy in patients followed at the centers of the authors' association (AISTOM), a correct follow-up approach for these patients is very important. A multicentric clinical trial was thus carried out to evaluate the efficacy of transstomal endoscopic exploration (TEE) of the residual colon, and data collection began on May 31, 1984. Nine hundred fifty-seven patients were submitted to TEE after curative abdominoperineal resection (Miles) for rectal cancer. The male-female ratio was 1.3; 89.6 percent of the patients were over 50 years of age. A family history of large-bowel cancer was present in 18 percent, and in 23 percent of the patients the cancer was associated with synchronous adenomas. Only 31 percent of the patients had colonoscopy or double-contrast barium enema x-ray beyond the neoplastic area before surgery. TEE was done in 96.8 percent of the patients; in 3.3 percent the examination was not possible, mainly for stenosis of the stoma (in 2.3 percent). In 82 percent of the patients a complete large-bowel exploration was possible: a new large, bowel cancer was found in 22 patients (2.2 percent) and an adenoma in 183 patients (19.1 percent). These results show that, because it is safe, practical, and effective, endoscopy plays an important role in the follow-up of ostomates.
Dis Colon Rectum 1987 Sep
PMID:Colonoscopy in ostomy patients. Results at the first postoperative examination. 330 86

Examination of 1014 consecutive autopsies revealed four early malignant lesions, comprising: 1) a carcinoma in situ arising from a large (2.5 cm) pedunculated adenomatous polyp; 2) a carcinoma in situ arising from a small (0.8 cm) flat adenoma; 3) an early invasive carcinoma arising from a flat (2.5 cm) adenoma, and 4) an early invasive polypoid adenocarcinoma (0.7 cm) with no identifiable remnants of adenoma. The early malignant lesions encountered in this study reaffirm the importance of the adenoma-cancer sequence in the pathogenesis of colorectal cancers in man. The malignant potential of flat adenomas is emphasized. The occurrence of small carcinomas without evidence of adenomatous elements raises the possibility of de novo origin as an alternative pathway. In the present study, one of four early colorectal cancers may have a de novo origin.
Dis Colon Rectum 1988 Apr
PMID:Early malignant lesions of the colorectum at autopsy. 335 99

Flow cytometric DNA analysis was performed on the colonic adenomas of 24 patients who had resection of an invasive colorectal carcinoma subsequent to polypectomy. The incidence of DNA aneuploidy among these adenomas was only 13 percent. Thus, simple recognition of colonic adenomas as being DNA diploid or DNA aneuploid is unlikely to be helpful for identifying patients with adenoma who are at high risk for developing a future colorectal carcinoma.
Dis Colon Rectum 1988 Jun
PMID:DNA aneuploidy in solitary colonic adenomas and the future risk of colorectal cancer. 337 64

Based on the adenoma-carcinoma sequence the authors studied whether determination of serum carcinoembryonic antigen (CEA) provided any conclusions concerning malignant transformation of a colorectal adenoma. In 32 patients with single or multiple adenomas, serum CEA did not differ from 119 healthy individuals. In 43 percent, a decrease of CEA could be observed after polypectomy, while it increased in 22 percent or remained unchanged in 35 percent. No correlation was found between adenoma volume and serum CEA. There was a tendency toward a higher serum CEA level in patients with villous adenoma as compared with those with tubular structure. CEA concentrations were independent from the degree of cellular atypia, but polypectomy was followed by a decrease of serum CEA in villous adenoma or of moderate cellular atypia, reflecting a possible influence on production or shedding of CEA by these subtypes of adenoma. The results indicate, therefore, that serum CEA is not able to recognize the malignant potential of colorectal adenoma.
Dis Colon Rectum 1987 Aug
PMID:Do size, histology, or cytology of colorectal adenomas and their removal influence serum CEA? 362 62

In 282 patients, 731 colon polyps (643 adenomas and 88 hyperplastic polyps) were extirpated endoscopically or biopsied and investigated histologically. Localization of the adenomas with various degrees of atypia and the hyperplastic polyps, as well as their size distribution, were determined. In 66 patients with adenoma polypectomy on the first examination, one or more control colonoscopies were carried out (in all, 107). The median period of follow-up observation was 31 months. Thirty percent of the one-year control colonoscopies after polypectomy revealed new adenomas. The statistical analyses showed that patients with singular adenomas, on initial investigation, develop significantly fewer adenomas in the further course than patients with multiple initial findings, especially in negative results in the one-year control. The size of new adenomas found during the first 24 months after polypectomy does not exceed 10 mm. On the basis of these results and the literature data available so far, a follow-up program is presented for discussion.
Dis Colon Rectum 1986 Jun
PMID:Colorectal adenomas. Distribution, incidence of malignant transformation, and rate of recurrence. 370 16


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