Kenichi Sugihara

Small “flat adenoma” of the large bowel with special reference to its clinicopathologic features

Thirty-three small “flat adenomas,” not more than 1 cm in diameter, were collected from surgically and colonoscopically removed specimens, and their colonoscopic and histologic characteristics were described. There were 14 adenomas with mild atypia, five with moderate atypia, 14 with severe atypia (or focal carcinoma limited to the mucosa). The grade of atypia seems to increase with the size of lesions, and these lesions were assumed to play an important role in the adenoma-carcinoma sequence. The importance of recognizing the presence of these small “flat adenomas” in everyday practice is stressed.

Diverticular disease of the colon in Japan a review of 615 cases

Of 615 patients with diverticular disease of the colon, 429 had diverticula in the cecum and ascending colon, 98 in the sigmoid and descending colon and 88 in both the right- and left-side colon. The right-sided type was, more common in younger people and more predominant in men, whereas the left-sided type was more common in the elderly and showed no difference in numbers between men and women. More than 50 per cent of patients were asymptomatic, and 25 per cent complained of disturbed bowel function. The frequency of diverticulitis was not related to location, but to the number of diverticula. Seventy-seven were complicated by acute inflammation (right-sided diverticulitis, 61, and left-sided diverticulitis, 16). Many patients with right-sided diverticulitis improved with medical treatment and the operative procedure of choice was drainage of the inflamed area with supplemental appendectomy.

Gardner's syndrome associated with periampullary carcinoma, duodenal and gastric adenomatosis

A 48-year-old man with Gardners syndrome, who had abdominoperineal resection for rectal carcinoma in 1962, was found to have an ulcerating growth of the duodenum, and pancreaticoduodenectomy was performed in 1979. Histologic examination by complete step-serial sectioning disclosed a well-differentiated adenocarcinoma with adenomatous remnants, a large adenoma with focal carcinoma, 256 adenomas of the duodenum, and 91 adenomas of the gastric antrum. The world medical literature was reviewed, and 29 cases of periampullary carcinoma and 12 cases of gastric carcinoma complicating familial polyposis coli or Gardners syndrome were analyzed.

Management of patients with invasive carcinoma removed by colonoscopic polypectomy

The management of patients with invasive carcinoma removed by colonoscopic polypectomy remains controversial. In order to assess the criteria for subsequent surgery after polypectomy, the histologic findings and outcome of 25 patients with invasive carcinomas treated by polypectomy were analyzed. Subsequent surgery was indicated when removed invasive carcinoma showed at least one of the following findings: 1) carcinoma near the surgical margin, 2) vessel invasion, 3) massive invasion, and 4) poorly differentiated adenocarcinoma. The authors considered those findings to be a risk factor for local residual carcinoma or lymph-node metastases, or both. Of 25 patients, 18 showed risk factors, with 16 receiving surgery. Only one had residual carcinoma in the lymphatic vessel of the surgical specimen. The remaining 15 had no carcinoma in the surgical specimens, however, one died of recurrent disease 55 months later. Two patients with risk factors received no surgery for various reasons. Local recurrent carcinoma developed in one 39 months later and the other had no recurrent carcinoma at autopsy. Seven patients without risk factors were adequately treated by polypectomy without recurrent disease 34 to 96 months later (average, 69 months). Consequently, of 18 patients with risk factors, 3 showed either residual carcinoma in the surgical specimens or recurrent carcinoma was found later. None of 7 patients without risk factors developed recurrent disease. We recommend that patients with risk factors be followed by surgery; however, patients without risk factors can be adequately treated by polypectomy alone.

Histopathologic comparison of colorectal adenomas in English and Japanese patients

Histopathologic comparison of colorectal adenomas removed at St. Marks Hospital, London, England, and those removed at the University of Tokyo, Japan was performed. There were 1242 lesions in the St. Marks series and 310 in the University of Tokyo series. All adenomas were removed either by colonoscopic polypectomy or hot biopsy. The indications and methods of colonoscopic removal were similar in the two series. Age distribution of the patients showed a younger peak incidence in the University of Tokyo series compared with the St. Marks patients. The percentage of adenomas larger than 1 cm, of tubulovillous or villous type, and with moderate or severe dysplasia were greater in the St. Marks series than in the University of Tokyo series. Percentages of adenomas with mild, moderate, or severe dysplasia in each category of size did not differ between the two series. In view of the fact that there is a high colorectal cancer risk in England and medium cancer risk in Japan, our results give further epidemiologic support to the concept of the adenoma-carcinoma sequence.

Clinicopathological study of white spots of the colonic mucosa around polyps, with special reference to the endoscopic diagnosis of invasive carcinoma

White spots were observed on the mucosa immediately adjacent to polyps and carcinomas; the majority of the polyps proved to be carcinoma in situ or had invasive carcinoma. The white spots consisted of accumulations of foamy cells with features similar to muciphage.

Clinicopathologic Features of Flat Adenoma of the Large Bowel

One hundred and twenty-three “flat adenomas” in 98 patients were collected from the polypectomy and surgically resected specimens, and colonoscopic & histologic characteristics were described. They consisted 9.5% of ordinary polypoid adenomas removed colonoscopically and tended to situate more evenly in the colon than ordinary polypoid adenomas although the commonest site was in the left colon and the rectum. More than 90% of them were under 1cm in diameter and 15% of them showed severe atypia. The importance of recognizing the presence of these small “flat adenomas” as a new precursor of colonic carcinoma was stressed.