Surgical management of large sessile villous and tubulovillous adenomas of the lower rectum

BACKGROUND: Large sessile adenomas of the rectum are premalignant lesions necessitating complete removal. METHODS: We reviewed the data on 20 consecutive patients with large (>or=2 cm) sessile villous and tubulovillous adenomas of the lower two thirds of the rectum (or=50% or an endosonographic staging of >or=uT2 underwent a low anterior resection of the rectum. The remaining 9 patients underwent a posterior full-thickness local bowel wall resection (modified Mason procedure). The median (range) follow-up period was 3.8 (0.7-8.2) years. RESULTS: Preoperative biopsy examination successfully excluded invasive carcinoma. Overstaging, however, occurred in 9 of 12 patients (75%) undergoing endosonography, resulting in surgical overtreatment of 4 patients. A curative resection (R0) was always achieved. Five patients had complications, but there was no in-hospital mortality and no cases of local recurrence. 4 out of 19 patients complained of minor stool incontinence, and 3 patients reported incomplete rectal emptying or constipation. Fourteen patients described the operative result as excellent (n = 7) or good (n = 7). CONCLUSIONS: Endosonography may lead to overstaging and overtreatment. An individualized approach based on the degree of adenomatous circumferential involvement and endosonographic staging showed no mortality, low morbidity, no local recurrence, and good functional medium-term results.     

Colorectal villous and tubulovillous adenomas equal to or greater than four centimeters.

The records of 237 patients treated for benign and malignant villous and tubulovillous adenomas at Roswell Park Memorial Institute from 1963 to 1987 were reviewed. Sixty-five adenomas were greater than or equal to 4 cm and form the basis of this report. Fifteen (23%) were in the cecum, 3 (5%) in the right colon, 1 (1%) in the splenic flexure, 10 (15%) in the sigmoid colon, and 36 (55%) in the rectum. The most common symptoms were rectal bleeding (70%), mucus diarrhea (44%), constipation (22%), and tenesmus (19%). Fifty-five (85%) of these large adenomas contained invasive adenocarcinoma and one in situ carcinoma. Two thirds of invasive carcinomas arose from predominantly villous adenomas and one third from tubulovillous adenomas. Half of all malignant adenomas demonstrated metastases to regional lymph nodes or distant metastases. Seven malignant adenomas (12%) were associated with synchronous adenocarcinomas of the colon, and 29% of malignant adenomas were associated with synchronous adenomatous polyps, principally tubular type. Four of nine benign, large adenomas were associated with synchronous adenomas but with no adenocarcinomas. No relationship was found between the size of the adenoma, location, or Dukes' stage. Though the incidence of in situ and invasive carcinomas is clearly related to the size of the adenoma, a linear relationship could not be demonstrated.     

Our experience in the transanal excision of tubulovillous adenomas of the rectum]

BACKGROUND: Personal experience on transanal excision of rectal adenomas without affecting sphincteric function is reported. METHODS: From 1985 to 1997, 27 patients suffering from rectal adenomatous polyps underwent surgery; the sites of lesions were within 3 to 10 cm from anal orifice in the whole series; the age of patients ranged from 30 to 81 years. Two different procedures were employed: the Parks' technique and the electroresection by traction flap technique according to Faivre. RESULTS: Any postsurgical complication such as hemorrhage, stenosis or incontinentia occurred; surgical mortality was absent. Histological examination disclosed severe dysplasia as well as in situ carcinoma in 6 patients (22.2%) and malignant polyps in 9 patients (33.3%). Only in a case a palliative excision was performed since the poor general conditions of this patient did not permit a more extended treatment; a local relapse of the tumour associated with liver metastases led the patient to death 22 months after surgery. Three patients were lost to follow-up and 2 patients died because of other causes, 6 and 8 years after surgical excision, respectively. CONCLUSIONS: The conclusions are is drawn that either Park's and Faivre's procedures are useful and safe for the surgical treatment of rectal villous polyps extended up to 8-12 cm from anal orifice, in spite of the presence of malignant foci within their mass. These surgical procedures are simple and relatively poor traumatic; for this reason they are more suitable than other transabdominal or abdomino-perineal approaches for older patients and other at risk-patients. It is underlined that the treated patients require a long-term follow-up aimed at the early diagnosis of possible relapses of adenomatosis.     

Treatment of ampullary villous adenomas that may harbor carcinoma

Villous adenoma of the ampulla of Vater is a rare tumor. It is a deceptive tumor because it is a premalignant lesion and biopsies of the lesion are false negative in 25% to 56% of patients. The primary focus of this report is 23 of 30 patients with villous adenoma of the ampulla of Vater who underwent Whipple operations. Paraffin blocks from 22 patients were available. In eight patients, blocks of the biopsies and the corresponding resected specimens were available. Immunohistochemical studies using antibodies to p53 and Ki-67 were performed to determine whether accumulation of these antibodies in the biopsy specimens would identify false negative biopsies. There was one operative death. The 2-, 5-, and 10-year survival rates for the 22 patients surviving a Whipple operation were 74%, 57%, and 35%, respectively. Three patients died of cancer. The mean p53 expression index was increased in adenomas to 88 (P = 0.001) and in carcinomas to 114 (P = 0.01), compared with 12.6 for normal ampullary epithelium adjacent to tumor. Significant differences in the Ki-67 proliferation index were noted between normal adjacent epithelium (13%), adenoma (34%, P = 0.0002), and carcinoma (53%, P = 0.034), as well as between adenomatous epithelium and carcinoma (34% vs. 53%, P = .012). Villous ampullary adenocarcinoma was present in 65% of patients with villous adenoma (87% if patients with carcinoma in situ in resected specimens are included). Because of the high false negative rate of ampullary biopsies, and the inability to accurately stage these lesions, we recommend pancreaticoduodenectomy in most patients. Studies with p53 and Ki-67 markers suggest that they may be helpful in the recognition of ampullary villous cancer not identified on routine biopsies.     

Transanal excision of rectal villous adenomas by laparoscopic methods

Large villous adenomas of the rectum are not uncommon and will be encountered often by general and colorectal surgeons in their practices. The approach to large adenomas can be via the colonoscope either transabdominally or transanally. A simple transanal method was instituted by the author in 1992 and has been used up to the time of writing. This involves using a 4-cm diameter transanal operating rectoscope with laparoscopic instruments and the laparoscope itself. The results for 13 patients from January 1992 to April 2001 are reviewed. The method is simple and allows access to lesions up to 15 cm from the anal verge with a low incidence of complications, residual disease, and recurrence.     

Impact of grade of dysplasia in villous adenomas of Vater's papilla

Therapeutic strategies for villous adenoma of the papilla of Vater remain controversial. This study evaluates the accuracy of preoperative histopathologic diagnosis and the impact of the grade of dysplasia on recurrence as well as on potential alteration of the surgical approach. A series of 32 patients with an adenoma of Vater's papilla who underwent local resection or pylorus-preserving pancreaticoduodenectomy between January 1990 and August 2000 were reviewed retrospectively. Multiple endoscopic biopsies had been performed preoperatively. The histopathology of the preoperatively obtained biopsy specimens and subsequent surgical specimens were evaluated for grade of dysplasia by two pathologists and correlated with the clinical course after operative treatment. Altogether, 3 of 11 patients (27%) with a low-grade (LG) dysplasia adenoma and 6 of 21 patients (29%) with a high-grade (HG) dysplasia adenoma in the initial endoscopic biopsy specimens exhibited invasive carcinoma at the postoperative histologic examination (NS). Recurrence was not observed in the 6 patients from the LG dysplasia adenoma group following local resection and benign postoperative histology. In contrast, recurrence of villous adenoma was discovered in 2 of 12 patients (17%) and development of invasive carcinoma in 5 of 12 patients (42%) from the preoperative HG dysplasia group (p <0.05). The overall risk of carcinoma after primary diagnosis of an HG dysplasia adenoma was 44% (14/32). Adenoma of the papilla of Vater including HG dysplasia appears to be associated with a high risk of exhibiting invasive carcinoma postoperatively and a high rate of recurrence. Therefore pylorus-preserving pancreaticoduodenectomy should be offered to patients with an HG dysplasia adenoma.     

直肠绒毛状腺瘤手术方式的探讨

目的 探讨直肠绒毛状腺瘤手术方式的合理选择。方法 对70例手术治疗的直肠绒毛状腺瘤病例进行回顾性研究及随访。经肛门括约肌径路切除(Mason术)29例，直肠前切除术(Dixon术)16例，经肛门局部切除(transanal excision，TE)11例，经骶部切除(Kraske术)5例，其他手术9例。结果 25例(35．7％)直肠绒毛状腺瘤已发生癌变。70例患术后并发症发生率为15．7％，术后复发率为14．3％。Mason术后并发症发生率和复发率分别为6．9％和0。结论 选择直肠绒毛状腺瘤的手术方式应综合考虑腺瘤的具体部位、大小以及术前活检的病理结果，对于腺瘤癌变的病例还应考虑肿瘤浸润肠壁的深度。Mason术是治疗直肠中下段绒毛状腺瘤的理想术式。     

Prognosis after treatment of villous adenomas of the colon and rectum.

With the existing evidence of neoplastic polyps of the colon and rectum as precursors of most or all colonic cancer, information of the short- and long-term course after treatment is a prerequisite of using the knowledge of the polyp-cancer sequence in an effective cancer prophylaxis. One hundred seventy-four patients treated for villous adenomas of the colon and rectum during the years 1960-1975 were re-examined. Survival and cure rates were estimated by actuarial analysis. The death rate of colonic cancer among patients treated for a benign villous adenoma was significantly higher than in an age and sex matched normal population, resulting in a significantly reduced crude survival rate among these patients. Almost all recurrences after treatment of benign villous adenomas occurred within the first four to five years recurrence rate of roughly 30%, indicating that five years seem to be an adequate total control period following treatment.     

Villous and tubulovillous adenomas of the colon and rectum. A retrospective review, 1964-1985

The records of 1,040 patients with 1,440 villous and tubulovillous adenomas of the colon and rectum treated at the Cleveland Clinic over a 21 year period were reviewed. The incidence of invasive adenocarcinoma was higher in patients with multiple adenomas at the time of presentation, in patients with a family history of colorectal cancer, and in those with adenomas greater than 4 cm in diameter. Eighty percent of the adenocarcinomas were Dukes' A or B, 15 percent were Dukes' C, and 5 percent presented with distant metastases. Clinical impression on examination was more accurate than biopsy in assessing the presence of malignancy in these tumors. Recurrence after local treatment of both benign and malignant tumors was high. Recurrence was significantly related to the size of the adenoma (more common when the tumor was more than 4 cm in diameter), location (more common when it was located in the rectum), and the type of treatment. Only 4 percent of the patients had died from colorectal cancer at the time of follow-up. The overall 5 year actuarial survival rate was 85 percent.     

Nd-YAG laser photoablation of sessile villous and tubular adenomas of the colorectum.

Neodymium (Nd)-YAG laser photoablation treatment was used to treat 46 patients with broad-based villous and tubular adenomas of the colon or rectum. These adenomas were distributed throughout the large bowel, with the majority (72%) located above the peritoneal reflection. Patients received an average of 2.1 treatments per adenoma, with 22 patients (48%) requiring only one treatment. Overall treatment success was achieved in 89% of cases (mean follow-up of 12 months), with four patients undergoing continued therapy. Of the patients who received a full course of treatment, only two (4%) were not taken to complete photoablation. Complications were minimal, and 92% of all laser treatments were done on an outpatient basis. Four patients had documented polyp recurrence that was controlled with additional laser treatment. Two patients with malignant polyps who were not surgical candidates were also treated with the laser, with no tumor recurrence seen at 11 and 14 months. Nd-YAG laser photoablation of large colonic polyps offers a safe, efficient, and cost-effective alternative to standard surgical resection.     

Clinical features of silent corticotroph adenomas

Background  

Silent corticotrph adenomas represent a distinct pathological subtype of non-functioning pituitary adenomas that are traditionally believed to carry a more aggressive biological behavior and higher potential for recurrence.     

Immunohistochemical and molecular features of sporadic and FAP-associated duodenal adenomas of the ampullary and nonampullary mucosa

The pathogenesis of duodenal adenomas is not well elucidated. Much of the literature pertains to ampullary adenomas and those associated with familial adenomatous polyposis (FAP). In this study, we evaluated the molecular features of a series of sporadic duodenal adenomas (n=22) that developed distal to the ampulla, and compared them with the features of sporadic ampullary adenomas (n=9) and FAP-related polyps (n=12). Using a combination of immunohistochemical studies [cytokeratins 7 and 20, E-cadherin, beta-catenin, p53, MLH-1, MSH-2, MSH-6, and O6-methylguanine methyltransferase (MGMT)], DNA sequencing [beta-catenin, adenomatous polyposis coli (APC), p53, KRAS, and BRAF], and a polymerase chain reaction-based microsatellite instability assay; we assessed each case for abnormalities in the Wnt signaling and mitogen-activated protein kinase pathways and DNA repair mechanisms. Wnt signaling pathway abnormalities occurred in sporadic, nonampullary (82%), and ampullary (77%) adenomas at comparable rates, usually reflecting nuclear beta-catenin immunostaining (64% and 44%, respectively), and APC rather than beta-catenin, mutations. KRAS mutations were infrequent in sporadic, nonampullary adenomas (18%), and FAP-related adenomas (9%); moderately frequent in ampullary adenomas (44%); and none of the cases harbored BRAF mutations. Only 4 (13%) sporadic adenomas showed nuclear p53 staining, but no p53 mutations were detected in exons 5 to 8. Loss of O-methylguanine methyltransferase immunostaining was identified in 1 sporadic, nonampullary adenoma, and none of the polyps in any group showed loss of MLH-1, MSH-2, or MSH-6 staining, or high-frequency microsatellite instability. We conclude that sporadic and FAP-related adenomas show similar molecular features, regardless of their anatomic location. Similar to colorectal adenomas, they harbor APC and KRAS mutations; but BRAF mutations, p53 alterations, and DNA mismatch repair abnormalities are rare.