Familial adenomatous polyposis

Familial adenomatous polyposis represents approximately 1% of all colorectal tumours and is caused by germline mutations in the adenomatous polyposis coli (APC) gene. A 38-year-old lady presented with abdominal pain, diarrhoea and iron deficiency anemia. There was no history of colorectal cancer in the family. Colonoscopy showed hundreds of polyps throughout the colon sparing the rectum, and an ulcerative tumour of the sigmoid colon. The diagnosis was familial adenomatous polyposis (FAP) and adenocarcinoma of the sigmoid colon. Colectomy with ileorectal anastomosis was performed and later on she was given chemotherapy and advice life long surveillance. The patient had one brother and one sister, without clinical symptoms. The brother had a single hyperplastic rectal polyp, while the sister refused colonoscopy. The patient has 2 sons, the elder son had normal colonoscopic findings, and the younger son was also diagnosed as a patient of FAP and referred for colectomy.     

Familial juvenile adenomatous polyposis

Most colonic polyps in children are of the juvenile type and occur either as single or scattered colonic polyps. The peak incidence occurs between 4 and 6 yr of age, with a spontaneous decline from 12 to 15 yr. Significant clinical symptoms are rare, and operative therapy is rarely indicated. Diffuse colonic juvenile polyposis, however, varies with different clinical, prognostic, and genetic implications.In infancy, colonic polyposis may be associated with diffuse gastrointestinal involvement leading to fatal complications unless treated aggressively. In childhood, colonic polyposis can occur with a genetic variance with an increased incidence of familial intestinal malignancies.Colonic polyposis in childhood, both familial and nonfamilial, can present with a mixed form of juvenile and adenomatous polyposis.In children with colonic polyposis, the biopsy of a single polyp that reveals the histologic appearance of a juvenile polyp does not rule out the simultaneous existence of adenomatous polyps.     

Familial adenomatous polyposis: Gardner's syndrome

Familial adenomatous polyposis (PAF) associated to soft tissue tumors or osteomas constitutes the Gardner's syndrome of autosomal dominant inheritance. The risk of colorectal cancer in these patients is 100%. We present a patient with Gardner's syndrome who was had colectomy at early age. An eleven years old boy he was evaluated due to a family history of PAF and subcutaneous tumors (occipital and left thigh). Genetic profile shows a mutation in gene APC and the colonoscopy confirms the polyposis; the biopsy also suggested moderate dysplasia. When the patient reached the age of twelve, a total colectomy with colorectal mucosectomy was performed. Cystic subcutaneous lesions (epidermoid cysts) were also excised. In the postoperative period there were no complications. The prophylactic colectomy, is the only effective treatment to prevent the colorectal cancer. Gardner's syndrome patients requires periodic controls to rule out the appearance of new tumors or anomalies in the retine. The duodenoscopy is essential in the follow up of these patients because of the frequency of duodenal affectation.     

Familial adenomatous polyposis. Initial experiences with the Heidelberg polyposis register]

In order to enable consequent screening in at risk persons and life-long follow-up in patients, a computer-based polyposis registry was initiated in 1991. It now includes data of 130 FAP patients and 179 risk persons from 87 families, that were seen in our clinic since 1982. 20.5% of the "probands" (symptomatic patients) had a colorectal carcinoma at the time of diagnosis in contrast to none in the "call-up" group. The most reliable screening method as yet has proven to be the flexible sigmoidoscopy with histological verification of the adenomatous nature of the polyps. Congenital hypertrophy of the retinal pigment epithelium was only seen in 50% of our patients. The exact localisation of the FAP gene in August 1991 will soon significantly improve the prognostic value of molecular genetic screening procedures. The improved prognostic value of the method will enable early and even prenatal diagnosis. It will not any more be necessary to wait for the phenotypic manifestation (colorectal polyps) in order to be sure of the diagnosis FAP.     

家族性腺瘤性息肉病的病因学及诊治进展

家族性腺瘤性息肉病(familial adenomatous polyposis,FAP)是一种常染色体显性遗性性肿瘤,发病率约为1/7000,占结直肠癌的1%左右~([1]).随着检测技术的提高,FAP的发病率呈上升趋势.一些以前被认为是独立的疾病.     

Familial adenomatous polyposis coli in South Africa--molecular basis and diagnosis.

OBJECTIVE: To determine the molecular basis and establish a routine molecular diagnostic service for familial adenomatous polyposis coli (FAP) families in South Africa. DESIGN: The coding region of the adenomatous polyposis coli (APC) gene in affected FAP kindreds was screened using heteroduplex analysis, single-strand conformation polymorphism analysis and the protein truncation test. SETTING: Department of Human Genetics, University of Stellenbosch, and the Cancer Research Campaign Laboratories, Department of Pathology, University of Edinburgh and Molecular Medicine Centre, Western General Hospital, Edinburgh, Scotland (academic visit of 6 months). SUBJECTS: FAP-affected individuals and at-risk family members in 28 apparently unrelated South African families. RESULTS: A total of nine different APC mutations was identified, allowing DNA-based diagnosis in 20 families. Three of these mutations have not been described previously in other populations. CONCLUSION: Pre-symptomatic diagnosis using direct mutation detection is cost-effective and surgical intervention has the potential to prevent cancer in at-risk individuals from FAP families.     

Familial adenomatous polyposis: review of the literature and report of 3 cases

The Authors describe three cases of Familial Adenomatous Polyposis, (FAP), in patients of the same family, mother and two daughters, with different stages of the disease. Familial adenomatous polyposis is a mendelian dominant inherited syndrome with an incidence of 1:11,000, caused by an alteration of APC gene, which causes multiple disorders of the development ecto-, endo- and mesoderma. The syndrome is characterized by the presence of adenomatous polyps in the gastroenteric tract, mostly in colon-rectum and duodenum with demonstrated adenoma-carcinoma sequence. In the family here reported a case of familial adenomatous polyposis at the adenomatous stage and two of cancer of colon-rectum are registered. In the first case surgery had a preventive aim, and ileo-rectal anastomosis was performed; in the other two cases the treatment was Miles operation with radical intention.     

Familial adenomatous polyposis: prevalence of adenomas in the ileal pouch after restorative proctocolectomy

OBJECTIVES: To determine the prevalence of adenomas in ileal pouches from patients with familial adenomatous polyposis (FAP) and to determine whether a correlation exists between the presence of pouch adenomas and duodenal adenomas and the site of the adenomatous polyposis coli gene mutation. SUMMARY BACKGROUND DATA: Restorative proctocolectomy can markedly reduce the risk of colorectal adenocarcinoma in FAP patients. However, adenomas with the potential to progress to adenocarcinoma can develop in the duodenum, ileum, and continent ileostomy after restorative proctocolectomy. More recently, adenomas have been described in the ileal pouch after ileoanal anastomosis. METHODS: Pouch endoscopy was offered to 167 patients with FAP who had undergone restorative proctocolectomy between January 1984 and December 1996. RESULTS: Adenomas were found in 35% of the 85 ileal pouches examined. No invasive carcinomas were noted. The risk of developing one or more adenomas at 5, 10, and 15 years was 7%, 35%, and 75%, respectively. Patients with adenomas were more likely to have duodenal and ampullary adenomas. No correlation was detected between adenoma development and the site of the adenomatous polyposis coli mutation. CONCLUSIONS: Adenomas are frequently found in the ileal pouch of patients after restorative proctocolectomy for FAP. Regular endoscopic surveillance of the pouch is recommended at a frequency similar to that of upper gastrointestinal endoscopy.     

Familial adenomatous polyposis predisposes to pathologic exposure of the stomach to bilirubin

BACKGROUND: The role of duodenogastric reflux in the genesis of gastric polyps in familial adenomatous polyposis (FAP), although suggested by scintigraphy scanning studies, remains unclear. METHODS: Twenty-four hour intragastric bilirubin monitoring with the Bilitec optoelectronic device was carried out in 25 FAP patients, of whom 19 had gastric polyps (fundic gland in 13, adenomatous in 2, and both histologic types in 4) on endoscopic examination. Gastric exposure to bilirubin was expressed as the percentage of total recording time that absorbance exceeded the threshold of 0.25 and was calculated in reference to values obtained from 25 healthy volunteers. Helicobacter pylori status of the stomach was checked as well. RESULTS: Gastric exposure to bilirubin was pathologic in 14 (56%) patients. Gastric exposure to bilirubin was of longer duration in FAP patients than in healthy volunteers (mean+/-SEM: 19%+/-4% vs 6%+/-2%) (P<.005). It increased from healthy volunteers (6%+/-2%) to FAP patients without gastric polyps (10%+/-3%), and to FAP patients with gastric polyps (22%+/-5%) (P<.004). Bilirubin exposure times were similar in FAP patients with fundic gland polyps only and in those having either adenomatous polyps only or both types of polyps (24%+/-7% vs 17%+/-4%). No patient with pathologic gastric exposure to bilirubin as well as none having gastric polyps, had H. pylori in the antrum. CONCLUSIONS: This study shows that gastric exposure to bilirubin is of longer duration in FAP patients than in healthy volunteers, and in FAP patients with gastric polyps than in those without polyps. This study supports the existence of a direct correlation between pathologic duodenogastric reflux (DGR), the absence of H. pylori in the antrum, and the presence of gastric polyps in FAP patients.     

家族性腺瘤性息肉病

温习近十年来有关家族性腺瘤性息肉病的文献 ,结合笔者在临床上对此病诊断和治疗的经验 ,对该病的遗传、病理及临床特点 ,诊断和治疗方面的进展作一综述 ,以增加对此病的认识 ,有助于正确处理家族性腺瘤性息肉病。