Histogenesis of microscopic adenoma and hyperplastic (metaplastic) gland in nonpolyposis coli

The frequency of dysplastic branching crypts in colorectal polypoid tubular adenomas

Dysplastic crypt branching (DCB) was recently found in ulcerative colitis-associated dysplasia. The aim was to assess the frequency and the branching phenotype of DCB in polypoid colorectal tubular adenomas (TA). A total of 3956 DCB were found in the 139 TA: 98% were in asymmetric branching (DCAB) and the remaining 2% in symmetric branching (DCSB). A linear correlation was found between DCB frequency and the increasing digital size in TA (p < .05). Using a digital ruler, adenomas were divided into small TA (<5 mm) and larger TA (≥5 mm). The difference between the frequency of DCB in small TA (n = 75) vs. larger TA (n = 64), was significant (p < .05). DCB frequency was not influenced by age, gender or TA localization. In the normal colorectal mucosa (≈2 m² ), only occasional CSB is found and no CAB. And yet, multiple DCB (mean 16.7 DCB), mostly DCAB, was found in small TA, occupying <5 mm of the mucosal area. In larger TA, as many as 42.1 DCB (mean), mostly DCAB, occurred in merely 7.8 mm (mean) of the colon mucosa. Thus it is suggested that DCB is a standard histologic element of TA. The natural expansion of the adenomatous tissue in larger TA appears to be follow on from newly produced, mostly DCAB, by DCSB and by the accumulation of their dysplastic offspring's progenies. The findings strongly suggest that DCB is a central microstructure in the histological events unfolding in polypoid colorectal TA.

Morphologic Changes, Mucin Secretion, Carcinoembryonic Antigen (Cea) and Peanut Lectin Reactivity in Colonic Mucosa of Patients at High Risk for Colorectal Cancer

We studied 393 endoscopic colonic biopsies from 72 patients, classified in different groups after assessment of their risk factors, using: histologic, histochemical and immunohistochemical techniques (CEA-PAP and PNA-Px). In high risk patients (Groups A and B) the most relevant modifications were dysplasia with hyposecretion and hyperplasia with sialomucin secretion (TR-type change); in Group A 31 adenomas and 19 hyperplastic polyps also were found. A premalignant nature of dysplasia and predysplastic significance of TR change were suggested: 1) by finding the same alterations in mucosa of Group E (colectomized patients for carcinoma at after 1 year); 2) by increasing expression of CEA and PNA-Px ligands; 3) by their absence in Group D (normal controls). Hyperplastic polyps were confirmed not to be premalignant lesions, but since they had peculiar characteristics (increased CEA and PNA-Px positivity, association with adenomas) it does not seem justified to regard them as lesions unrelated to colorectal cancer, especially when associated with other risk factors. CEA and PNA-Px reactivity correlated well with the risk evaluation and with morphohistochemical changes in the mucosa; the reactivity significantly increased from normal mucosa to dysplasia.

Aberrant crypt foci in the human colon: frequency and histologic patterns in patients with colorectal cancer or diverticular disease

Aberrant crypt foci are considered potential markers of colorectal cancer risk. The aim of this study was to analyze a large series of human aberrant crypt foci according to frequency, distribution, and histology. Aberrant crypt foci were identified in methylene blue-stained colonic mucosa from 103 patients undergoing surgery for colorectal cancer or diverticular disease. Foci were histologically classified into surface hyperplastic type, surface and glandular hyperplastic type, mixed hyperplastic and adenomatous type, and adenomatous type. The mean frequency of aberrant crypt foci (n = 720) was higher in the colorectal cancer group (0.20/cm2) than in the diverticular disease group (0.07/cm2), and in distal colonic segments than in proximal segments. Most of the histologically examined foci (n = 366) were hyperplastic (88.8%). Surface hyperplasia accounted for 30.6% and prevailed in small lesions. Surface and glandular hyperplasia accounted for 58.2% and prevailed in medium-sized to large foci. Partially or totally dysplastic foci accounted for 10.1% of examined lesions (10.8% and 2.8% in the colorectal cancer and diverticular disease groups, respectively). Most of them (94.6%) were composed of mixed hyperplastic and adenomatous crypts and prevailed in large lesions. The higher frequency of aberrant crypt foci in patients with colorectal cancer sustains their putative role as preneoplastic markers. The high rate of mixed hyperplastic and adenomatous lesions supports the possible adenomatous transformation of hyperplastic lesions.

Colonoscopic screening examination of relatives of patients with colorectal cancer. II. Relations between tumour characteristics and the presence of polyps

Colonoscopy was offered to 206 first-degree relatives of 181 patients operated on for colorectal cancer (CRC). Findings of polyps in relatives correlated with Dukes staging, extent of dedifferentiation and localization of tumour in the operated patient, and type of family relationship. Adenomas in relatives and Dukes staging of carcinoma in the patients were inversely related. Relatives of patients with Dukes stage A tumour had more than twice as many adenomas as and a higher prevalence of multiple adenomas than relatives of patients with advanced cancer at the time of operation. If the patient had polyp(s) in addition to tumour, the number of adenomas per relative was almost doubled. Hyperplastic polyps in relatives were associated with poorly differentiated carcinoma in their related patients. These results support the theory that not all CRC are derived from polyps and that adenoma-derived CRC may have a better prognosis than 'de novo' CRC. An adenoma prevalence risk table is also presented.

Minute cancers arising de novo in the human large intestine

In order to search for the histogenesis and progression of colorectal cancer, the background mucosas of 18 patients with a single colorectal cancer, apart from familial adenomatosis coli, were studied by a step sectioning method. Three early minute cancers (3-5 mm in diameter) were detected in the apparently normal mucosa, and two cancers in the adenoma (focal cancer in adenomatous polyp). The three early cancers had no evidence of preexisting adenoma, so they were considered to be de novo cancers. In form they were depressed, flat, and slightly elevated. In humans, de novo cancer has an important significance in histogenesis and treatment of colorectal cancer. Clinically, it is also important to recognize the early phase of colorectal cancer in flat type as well as polypoid type.

Background mucosal changes of primary advanced large intestinal cancer in patients without familial polyposis coli

In 337 cases of primary advanced large intestinal cancer in patients without familial polyposis coli, the risk factor for cancer was discussed chiefly from the background mucosa surrounding and apart from the cancers. The following findings were obtained: (1) in the mucosa surrounding cancers, adenoma was seen in 23 cases (6.8 per cent), adenomatous changes of the basal cells in 211 cases (62.6 per cent), and hyperplastic glands in 167 cases (49.6 per cent), (2) in the mucosa at least 10 mm from the cancers, adenoma, adenomatous changes of the basal cells, and hyperplastic glands were seen in 42 cases (12.5 per cent), 129 cases (38.3 per cent), and 40 cases (11.9 per cent), respectively. Therefore, it is suggested that microscopic adenoma and adenomatous changes of the basal cells might be a sign of premalignancy in patients without familial polyposis coli.

Comparative study of familial polyposis coli and nonpolyposis coli on the histogenesis of large-intestinal adenoma

The entire length of the large intestine resected from six patients with familial polyposis coli (FPC) was step-sectioned, and microscopic adenomas composed of one to several glands were prepared into complete serial sections. Histopathologic comparison of these microscopic adenomas was made between FPC and nonpolyposis coli (those not included in the special disease group of FPC). The histogenesis of adenomas in FPC and nonpolyposis coli was considered as follows. (1) In nonpolyposis coli, adenomas arise from basal cells of the deep layer of the mucosa. (2) In FPC, most of the adenomas (81.2 per cent) arise in the same manner as described above, although there are some (18.8 per cent) that appear to have arisen in the middle or superficial layer of the mucosa. (3) Therefore, it is believed that the morphologic difference of the large-intestinal mucosa between FPC and nonpolyposis coli comes not from the difference in the number of adenomas present but from the difference in the position and/or timing of appearance of adenomas.