Adenocarcinoma arising in the middle of ileoanal pouches: report of five cases

Ileal Pouch Cancer Detected More than 30 Years after Restorative Proctocolectomy for Ulcerative Colitis

INTRODUCTION

The standard surgical treatment for ulcerative colitis (UC) is proctocolectomy with hand-sewn ileoanal pouch anastomosis (hand-sewn IPAA) or stapled ileal pouch anastomosis (stapled IPAA). The occurrence of cancer in the ileal pouch after surgery for UC is rare, and a consensus on surveillance for ileal pouch cancer has not been reached. We report a case of ileal pouch cancer diagnosed by pouchoscopy 33 years after restorative proctocolectomy with IPAA for UC.

CASE PRESENTATION

A middle-aged man presented with positive fecal occult blood. The patient had undergone restorative proctocolectomy with IPAA for UC 33 years ago. Pouchoscopy had been performed every 2-3 years in the last 10 years. In April a year ago, he tested positive for fecal occult blood, and pouchoscopy revealed an ulcerative lesion and flat elevation in the ileal pouch on the proximal side of the ileoanal anastomosis. Targeted biopsies of the ulcerative lesion revealed low-grade dysplasia (LGD). After 4 months, pouchoscopy also showed an increase in the size of the flat elevation, but targeted biopsies of this lesion also showed LGD. One year later in August, endoscopic examination for hematochezia showed a full circumferential raised lesion with a white coat and mucus draining from a fistula near the anastomosis at the same site. Pathological examination identified adenocarcinoma in the ileal mucosa. The preoperative diagnosis was ileal pouch cancer after restorative proctocolectomy with IPAA for UC, cT4bN2M0 stage IIIB (UICC-TNM, 8th), and he underwent excision of the ileal pouch body and the ileoanal anastomosis. Pathological examination showed mucinous carcinoma in the ileal mucosa with chronic inflammation. The postoperative stage was pT3N0M0 stage IIA; no postoperative chemotherapy was administered, and at 6 months postoperatively, the patient remained recurrence free.

CONCLUSION

Although ileal pouch cancer is rare, it can occur after a long period following ileal pouch surgery for UC. Endoscopic surveillance for ileal pouch cancer should be performed for early diagnosis and radical resection, especially if ileal pouch cancer occurs more than 10 years after the onset of UC.

Endoscopic management of patients with familial adenomatous polyposis after prophylactic colectomy or restorative proctocolectomy - systematic review of the literature

BACKGROUND

Patients with familial adenomatous polyposis (FAP) develop early colorectal adenomas and if left untreated, progression to cancer is an inevitable event. Prophylactic surgery does not prevent further development of cancer in the rectal remnant, rectal cuff in patients with ileal pouch anal anastomosis (IPAA) and even on the ileal mucosa of the pouch body. The aim of this review is to assess long-term rates of cancer and adenoma development in patients with FAP after prophylactic surgery and to summarise current recommendations for endoscopic management and surveillance of these patients.

MATERIALS AND METHODS

A systematic literature search of studies from January 1946 through to June 2023 was conducted using the PRISMA checklist. The electronic database PubMed was searched.

RESULTS

Fifty-four papers involving 5010 patients were reviewed. Cancer rate in the rectal remnant was 8.8-16.7% in the western population and 37% in the eastern population. The cumulative risk of cancer 30 years after surgery was 24%. Mortality due to cancer in the rectal remnant is 1.1-11.1% with a 5-year survival rate of 55%. The adenoma rate after primary IPAA was 9.4-85% with a cumulative risk of 85% 20 years after surgery and a cumulative risk of 12% for advanced adenomas 10 years after surgery. Cumulative risk for adenomas after ileorectal anastomosis (IRA) was 85% after 5 and 100% after 10 years. Adenomas developed more frequently after stapled (33.9-57%) compared to hand-sewn (0-33%) anastomosis. We identified reports of 45 cancers in patients after IPAA of which 30 were in the pouch body and 15 in the rectal cuff or at the anastomosis.

CONCLUSIONS

There was a significant incidence of cancer and adenomas in the rectal remnant and ileal pouch of FAP patients during the long-term follow-up. Regular endoscopic surveillance is recommended, not only in IRA patients, but also in pouch patients after proctocolectomy.

Cancer in the Anal Transition Zone and Ileoanal Pouch following Surgery for Ulcerative Colitis

Restorative proctocolectomy with ileal pouch-anal anastomosis remains the gold standard treatment for patients with ulcerative colitis who desire restoration of intestinal continuity. Despite a significant cancer risk reduction after surgical removal of the colon and rectum, dysplasia and cancers of the ileal pouch or anal transition zone still occur and are a risk even if an anal canal mucosectomy is performed. Surgical care and maintenance after ileoanal anastomosis must include consideration of malignant potential along with other commonly monitored variables such as bowel function and quality of life. Cancers and dysplasia of the ileal pouch are rare but sometimes difficult-to-manage sequelae of pouch surgery.

Management of pouch neoplasia: consensus guidelines from the International Ileal Pouch Consortium

Surveillance pouchoscopy is recommended for patients with restorative proctocolectomy with ileal pouch-anal anastomosis in ulcerative colitis or familial adenomatous polyposis, with the surveillance interval depending on the risk of neoplasia. Neoplasia in patients with ileal pouches mainly have a glandular source and less often are of squamous cell origin. Various grades of neoplasia can occur in the prepouch ileum, pouch body, rectal cuff, anal transition zone, anus, or perianal skin. The main treatment modalities are endoscopic polypectomy, endoscopic ablation, endoscopic mucosal resection, endoscopic submucosal dissection, surgical local excision, surgical circumferential resection and re-anastomosis, and pouch excision. The choice of the treatment modality is determined by the grade, location, size, and features of neoplastic lesions, along with patients' risk of neoplasia and comorbidities, and local endoscopic and surgical expertise.

Incidence and Risk Factors of Cancer in the Anal Transitional Zone and Ileal Pouch following Surgery for Ulcerative Colitis and Familial Adenomatous Polyposis

Proctocolectomy with ileal pouch-anal anastomosis is the intervention of choice for ulcerative colitis and familial adenomatous polyposis requiring surgery. One of the long-term complications is pouch cancer, having a poor prognosis. The risk of high-grade dysplasia and cancer in the anal transitional zone and ileal pouch after 20 years is estimated to be 2 to 4.5% and 3 to 10% in ulcerative colitis and familial polyposis, respectively. The risk factors for ulcerative colitis are the presence of pre-operative dysplasia or cancer, disease duration > 10 years and severe villous atrophy. For familial polyposis, the risk factors are the number of pre-operative polyps > 1000, surgery with stapled anastomosis and the duration of follow-up. In the case of ulcerative colitis, a pouchoscopy should be performed annually if one of the following is present: dysplasia and cancer at surgery, primary sclerosing cholangitis, villous atrophy and active pouchitis (every 5 years without any of these factors). In the case of familial polyposis, endoscopy is recommended every year including chromoendoscopy. Even if anal transitional zone and ileal pouch cancers seldom occur following proctectomy for ulcerative colitis and familial adenomatous polyposis, the high mortality rate associated with this complication warrants endoscopic monitoring.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2020 for the Clinical Practice of Hereditary Colorectal Cancer

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (Translated Version)

Hereditary colorectal cancer accounts for less than 5% of all colorectal cancer cases. Some of the unique characteristics that are commonly encountered in cases of hereditary colorectal cancer include early age at onset, synchronous/metachronous occurrence of the cancer, and association with multiple cancers in other organs, necessitating different management from sporadic colorectal cancer. While the diagnosis of familial adenomatous polyposis might be easy because usually 100 or more adenomas that develop in the colonic mucosa are in this condition, Lynch syndrome, which is the most commonly associated disease with hereditary colorectal cancer, is often missed in daily medical practice because of its relatively poorly defined clinical characteristics. In addition, the disease concept and diagnostic criteria for Lynch syndrome, which was once called hereditary non-polyposis colorectal cancer, have changed over time with continual research, thereby possibly creating confusion in clinical practice. Under these circumstances, the JSCCR Guideline Committee has developed the "JSCCR Guidelines 2016 for the Clinical Practice of Hereditary Colorectal Cancer (HCRC)," to allow delivery of appropriate medical care in daily practice to patients with familial adenomatous polyposis, Lynch syndrome, or other related diseases. The JSCCR Guidelines 2016 for HCRC were prepared by consensus reached among members of the JSCCR Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR Guidelines 2016 for HCRC.

Adenocarcinoma of the ileal pouch mucosa: case report and literature review

PURPOSE

Cancers developing near the site of the ileoanal pouch anastomosis (IPAA) have been reported, but uncommonly in the ileal pouch mucosa itself. We present a recently encountered case of ileal pouch cancer and review the literature to examine the prevalence, risk factors, and natural history of ileal pouch adenocarcinoma as well as pouch surveillance.

METHODS

A chart review of the case from our institution was conducted, and a PubMed search was undertaken for articles describing adenocarcinoma arising from the ileal pouch mucosa.

RESULTS

Twenty articles containing 26 cases were reviewed in addition to our described case. More than half were reported in the last decade. Only three cases were definitively stage 1. All seven patients who underwent regular surveillance were diagnosed with stage 1 or 2 disease. Seventeen patients had neoplasia in their original proctocolectomy specimen and six did not. The mean time from pouch creation to adenocarcinoma was 8.9 years.

CONCLUSIONS

The risk of developing ileal pouch mucosa adenocarcinoma appears low. However, increasing reports of these cancers are concerning as most patients present with advanced disease after many years. Patients with a previous history of dysplasia/cancer may be at increased risk. We believe surveillance after IPAA should include the anal transition zone and the ileal pouch mucosa. The establishment of expert consensus guidelines on pouch surveillance should be considered in the near future.

Disease course and management strategy of pouch neoplasia in patients with underlying inflammatory bowel diseases

BACKGROUND

To evaluate the disease course and management strategy for pouch neoplasia.

METHODS

Patients undergoing ileal pouch surgery for underlying ulcerative colitis who developed low-grade dysplasia (LGD), high-grade dysplasia, or adenocarcinoma in the pouch were identified.

RESULTS

All eligible 44 patients were evaluated. Of the 22 patients with initial diagnosis of pouch LGD, 6 (27.3%) had persistence or progression after a median follow-up of 9.5 (4.1-17.6) years. Family history of colorectal cancer was shown to be a risk factor associated with persistence or progression of LGD (P = 0.03). Of the 12 patients with pouch high-grade dysplasia, 5 (41.7%) had a history of (n = 2, 16.7%) or synchronous (n = 4, 33.3%) pouch LGD. Pouch high-grade dysplasia either persisted or progressed in 3 patients (25.0%) after the initial management, during a median time interval of 5.4 (2.2-9.2) years. Of the 14 patients with pouch adenocarcinoma, 12 (85.7%) had a history of (n = 2, 14.3%) or synchronous dysplasia (n = 12, 85.7%). After a median follow-up of 2.1 (0.6-5.2) years, 6 patients with pouch cancer (42.9%) died. Comparison of patients with a final diagnosis of pouch adenocarcinoma (14, 32.6%), and those with dysplasia (29, 67.4%) showed that patients with adenocarcinoma were older (P = 0.04) and had a longer duration from IBD diagnosis or pouch construction to the detection of pouch neoplasia (P = 0.007 and P = 0.0013).

CONCLUSIONS

The risk for progression of pouch dysplasia can be stratified. The presence of family history of colorectal cancer seemed to increase the risk for persistence or progression for patients with pouch LGD. The prognosis for pouch adenocarcinoma was poor.

Systematic review of cuff and pouch cancer in patients with ileal pelvic pouch for ulcerative colitis

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is the procedure of choice for refractory or complicated ulcerative colitis (UC). Since 1990, pouch-related adenocarcinomas have been described. The aim of this study was to review the literature to evaluate the burden of this complication, seeking for risk factors, prevention, and ideal management.

METHODS

We performed a systematic review of the literature to identify all described pouch-related adenocarcinoma in patients operated on with IPAA for UC. Studies were thoroughly evaluated to select authentic de novo pouch carcinomas. Some authors were contacted for additional information. Data of patients were pooled. Meta-analyses of suitable studies were attempted to identify risk factors.

RESULTS

Thirty-four articles reported on 49 patients (2:1, male:female) who developed unequivocal pouch-related adenocarcinoma, 14 (28.6%) and 33 (67.3%) arising from the pouch and anorectal mucosa, respectively. Origin was not reported in 2 (4%). Pooled cumulative incidence of pouch-related adenocarcinoma was 0.33% (95% confidence interval [CI], 0.31-0.34) 50 years after the diagnosis and 0.35% (95% CI, 0.34-0.36) 20 years after IPAA. Primary pouch cancer incidence was below 0.02% 20 years after IPAA. Neoplasia on colectomy specimen was the strongest risk factor (odds ratio, 8.8; 95% CI, 4.61-16.80). Mucosectomy did not abolish the risk of subsequent cancer but avoiding it increased 8 times the risk of cancer arising from the residual anorectal mucosa (odds ratio, 8; 95% CI, 1.3-48.7; P = 0.02). Surveillance is currently performed yearly starting 10 years since diagnosis, but cancers escaping this pathway are reported. In patients receiving mucosectomy, a 5-year delay for surveillance could be proposed.

CONCLUSIONS

Pouch-related adenocarcinomas are rare. Diagnosis of Crohn's disease in the long term may further decrease the rates in UC. Presumed evolution from dysplasia might offer a time window for cancer prevention. Abdominoperineal excision should be recommended for pouch-related adenocarcinomas.

Non-colorectal intestinal tract carcinomas in inflammatory bowel disease: results of the 3rd ECCO Pathogenesis Scientific Workshop (II)

Patients with inflammatory bowel diseases (IBD) have an excess risk of certain gastrointestinal cancers. Much work has focused on colon cancer in IBD patients, but comparatively less is known about other more rare cancers. The European Crohn's and Colitis Organization established a pathogenesis workshop to review what is known about these cancers and formulate proposals for future studies to address the most important knowledge gaps. This article reviews the current state of knowledge about small bowel adenocarcinoma, ileo-anal pouch and rectal cuff cancer, and anal/perianal fistula cancers in IBD patients.

Risk of ileal pouch neoplasms in patients with familial adenomatous polyposis

Restorative proctocolectomy is the most common surgical option for patients with familial adenomatous polyposis (FAP). However, adenomas may develop in the ileal pouch mucosa over time, and even carcinoma in the pouch has been reported. We therefore reviewed the prevalence, nature, and treatment of adenomas and carcinoma that develop after proctocolectomy in the ileal pouch mucosa in patients with FAP. In 25 reports that were reviewed, the incidence of adenomas in the ileal pouch varied from 6.7% to 73.9%. Several potential factors that favor the development of pouch polyposis have been investigated, but many remain controversial. Nevertheless, it seems certain that the age of the pouch is important. The risk appears to be 7% to 16% after 5 years, 35% to 42% after 10 years, and 75% after 15 years. On the other hand, only 21 cases of ileal pouch carcinoma have been recorded in the literature to date. The diagnosis of pouch carcinoma was made between 3 to 20 years (median, 10 years) after pouch construction. Although the risk of malignant transformation in ileal pouches is probably low, it is not negligible, and the long-term risk cannot presently be well quantified. Regular endoscopic surveillance, especially using chromoendoscopy, is recommended.

The prevalence of dysplasia in the ileoanal pouch following restorative proctocolectomy for ulcerative colitis with associated dysplasia

AIM

A recent systematic review indicated that dysplasia present before restorative proctocolectomy is a predictor of subsequent dysplasia in the pouch. This prospective study was carried out to assess the prevalence of dysplasia in the ileal pouch in patients having RPC for ulcerative colitis with co-existing dysplasia in the operation specimen.

METHOD

Eligible patients were invited for a surveillance endoscopy. The afferent and blind efferent ileal loop, ileoanal pouch and rectal cuff were examined by standard endoscopy using a dye-spray technique with methylene blue. Mucosal abnormalities were biopsied and random biopsies were taken from the afferent and blind ileal loop, pouch and rectal cuff.

RESULTS

Fourty-four patients (25 male, mean 49 years) underwent pouch endoscopy at a mean interval from RPC of 8.6 years. Dysplasia was detected in two (4.5%) patients. In one, low-grade dysplasia was found in the rectal cuff and in the other low-grade dysplasia was detected in random biopsies from the pouch and the efferent ileal loop.

CONCLUSION

This prospective pouch-endoscopy study detected dysplasia in < 5% of patients over nearly 10 years. The benefit of routine surveillance for dysplasia in the pouch is uncertain, as the significance of low-grade dysplasia in the pouch is not clear.

Inflammatory bowel disease-associated colorectal cancer: proctocolectomy and mucosectomy do not necessarily eliminate pouch-related cancer incidences

BACKGROUND

Colorectal cancer (CRC), the most lethal long-term complication of inflammatory bowel disease (IBD), is the culmination of a complex sequence of molecular and histologic derangements of the colon epithelium that are initiated and at least partially sustained by prolonged chronic inflammation. Dysplasia, the earliest histologic manifestation of this process, plays an important role in cancer prevention by providing the first clinical alert that this sequence is under way and by serving as an endpoint in colonoscopic surveillance of patients at high risk for CRC. Restorative proctocolectomy (RPC) is indicated for patients with IBD, specifically for ulcerative colitis that is refractory to medical treatment, emergency conditions, and/or in case of neoplastic transformation. Even after RPC with mucosectomy, pouch-related carcinomas have recently been reported with increasing frequency since the first report in 1984. We review IBD-associated CRC and pouch-related neoplasia prevalence, adverse events, risk factors, and surveillances.

METHODS

Literature of IBD-associated CRC patients and those undergoing RPC surgeries through 2010 were prospectively reviewed.

RESULTS

We found 12 studies from retrospective series and 15 case reports. To date, there are 43 reported cases of pouch-related cancers. Thirty-two patients had cancer in the anal transit zone (ATZ); of these, 28 patients had mucosectomy. Eleven patients had cancer found in the pouch body.

CONCLUSION

RPC with mucosectomy does not necessarily eliminate risks. There is little evidence to support routine surveillance of pouch mucosa and the ATZ except for patients associated with histological type C changes, sclerosing cholangitis, and unremitting pouchitis.

Diagnosis and management of dysplasia and cancer of the ileal pouch in patients with underlying inflammatory bowel disease

Approximately 30% of the patients with ulcerative colitis (UC) would ultimately require colectomy for medically refractory UC or UC-associated neoplasia. Restorative proctocolectomy with ileal pouch-anal anastomosis has become the surgical treatment of choice for these patients. However, this procedure does not completely abolish the risk for neoplasia of the pouch. The main risk factor for pouch neoplasia is a preoperative diagnosis of UC-associated dysplasia or cancer. Although the natural history and prognosis of pouch dysplasia are not clear, mortality associated with pouch cancer, once diagnosed, appears to be high. Conversely, not all pouch neoplasia follows the chronic inflammation-dysplasia-cancer sequence, which makes pouch endoscopy with biopsy, the current gold standard for surveillance, challenging. In addition, the findings that pouch neoplasia is not common and that pouch endoscopy still misses dysplasia lead to controversy on the need and time interval of routine endoscopic surveillance. However, based on reports in the literature and their own experience, the authors recommend surveillance endoscopy to be performed in patients at risk, such as those with a precolectomy diagnosis of UC-associated neoplasia. This review appraises issues in the prevalence and incidence, risk factors, technical aspects of pouch construction, clinical and pathological features, natural history, surveillance examination, diagnosis, and management of pouch neoplasia.

Oncologic outcome in patients with ulcerative colitis associated with dyplasia or cancer who underwent stapled or handsewn ileal pouch-anal anastomosis

PURPOSE

Ulcerative colitis is a risk factor for colorectal cancer. Restorative proctocolectomy with ileal pouch-anal anastomosis is a standard surgical management of patients with ulcerative colitis who have cancer or dysplasia, but the oncologic risk of stapled anastomosis vs mucosectomy with handsewn anastomosis is debated. We compare the risk of new cancer or recurrence in the pouch or rectal cuff in patients with ulcerative colitis undergoing stapled anastomosis vs mucosectomy with handsewn anastomosis.

METHODS

This study was performed as a retrospective analysis of the clinical database at a single center, Mount Sinai Hospital, Toronto, Canada. The patients with ulcerative colitis associated with colorectal dysplasia or cancer who underwent ileal pouch-anal anastomosis between 1981 and 2009 were evaluated. The development of dysplasia or cancer at ileoanal anastomosis or in the pelvic pouch was assessed.

RESULTS

Eighty-one patients underwent stapled (n = 59) or handsewn (n = 22) ileal pouch-anal anastomosis; 52 had evidence of dysplasia and 29 had colorectal cancer (24 colon; 5 rectum) at the time of surgery. Median follow-up was 76.1 months. Two of 10 (20%) patients with handsewn anastomosis and 0% patients with stapled anastomosis developed metastatic cancer. One patient with a 33-year history of colitis, a previously resected right-sided colon cancer, and subsequent high-grade dysplasia in the rectum underwent a handsewn pelvic pouch and developed an unresectable adenocarcinoma at the cuff 4 years later. A second patient with a 10-year history of colitis underwent handsewn pelvic pouch and developed dysplasia in the pouch 8 years after surgery. Nine patients were dead at last follow-up (11%). Of those patients, both colorectal cancer-related deaths were in patients with handsewn anastomoses. Differences in overall 5-year survival between the groups did not reach statistical significance. This study was limited by the sample size in subgroups and the few outcome events.

CONCLUSIONS

Performing a stapled ileal pelvic anal anastomosis does not appear to be inferior to mucosectomy and handsewn anastomosis in oncologic outcome, and it seems appropriate in patients with ulcerative colitis associated with coexisting dysplasia or cancer.

Preoperative colorectal neoplasia increases risk for pouch neoplasia in patients with restorative proctocolectomy

BACKGROUND & AIMS

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has substantially reduced the risk for ulcerative colitis (UC)-associated dysplasia or cancer (neoplasia). We characterized features, risk factors, and outcomes of pouch neoplasia in patients with inflammatory bowel disease in a historical cohort study.

METHODS

A total of 3203 patients with a preoperative diagnosis of inflammatory bowel disease underwent restorative proctocolectomy with IPAA from 1984 to 2009 at the Cleveland Clinic. Demographic, clinical, and endoscopic data were reviewed and samples were examined by histological analyses. Univariable and Cox regression analyses were performed.

RESULTS

Cumulative incidences for pouch neoplasia at 5, 10, 15, 20, and 25 years were 0.9%, 1.3%, 1.9%, 4.2%, and 5.1%, respectively. Thirty-eight patients (1.19%) had pouch neoplasia, including 11 (0.36%) with adenocarcinoma of the pouch and/or the anal-transitional zone (ATZ), 1 (0.03%) with pouch lymphoma, 3 with squamous cell cancer of the ATZ, and 23 with dysplasia (0.72%). In the Cox model, the risk factor associated with pouch neoplasia was a preoperative diagnosis of UC-associated cancer or dysplasia, with adjusted hazard ratios of 13.43 (95% confidence interval: 3.96-45.53; P < .001) and 3.62 (95% confidence interval: 1.59-8.23; P = .002), respectively. Mucosectomy did not protect against pouch neoplasia.

CONCLUSIONS

Risk for neoplasia in patients with UC and IPAA is small and not eliminated by colectomy or mucosectomy. A preoperative diagnosis of dysplasia or cancer of colon or rectum is a risk factor for pouch dysplasia or adenocarcinoma.

Intramucosal adenocarcinoma of the ileum originated 40 years after ileosigmoidostomy

Background

Small bowel adenocarcinomas (SBAs) are rare carcinomas. They are asymptomatic and usually neither endoscopy nor contrast studies are performed for screening

Case presentation

A 72-year-old Japanese male had a positive fecal occult blood test at a regular check-up in 2006. He suffered appendicitis and received an ileosigmoidostomy in 1966. A colonoscopy revealed an irregular mucosal lesion with an unclear margin at the ileum side of the anastomosis. A mucosal biopsy specimen showed adenocarcinoma histopathologically. Excision of the anastomosis was performed for this patient. The resected specimen showed a flat mucosal lesion with a slight depression at the ileum adjacent to the anastomosis. Histological examination revealed a well differentiated intramucosal adenocarcinoma (adenocarcinoma in situ). Immunohistological staining demonstrated the overexpression of p53 protein in the adenocarcinoma.

Conclusion

Adenocarcinoma of the ileum at such an early stage is a very rare event. In this case, there is a possibility that the ileosigmoidostomy resulted in a back flow of colonic stool to the ileum that caused the carcinogenesis of the small intestine.