Gallbladder dysplasia in patients with familial adenomatous polyposis

Risk of extracolonic malignancies and metachronous rectal cancer after colectomy and ileorectal anastomosis in familial adenomatous polyposis

BACKGROUND

Analysis of long-term clinical outcomes of patients with familial adenomatous polyposis is critical in reducing or preventing the incidence of extracolonic malignancies after initial surgery. The aim of the present study was to clarify the long-term outcomes, and establish a surveillance strategy for surgically treated familial adenomatous polyposis patients.

METHODS

Between January 1967 and March 2020, retrospective data were collected from 37 patients with familial adenomatous polyposis treated or monitored in our department. Occurrence of metachronous cancers, including rectal cancers and extracolonic malignancies, and other diseases was analyzed.

RESULTS

The median follow-up duration after the first surgery was 13.8 years. Initially, 16 patients underwent total proctocolectomy with ileal pouch-anal anastomosis, 18 underwent total colectomy with ileorectal anastomosis, and three underwent other procedures. A secondary proctectomy was performed for 9 of the 18 patients who underwent ileorectal anastomosis. Rectal cancer was diagnosed in 6 patients who underwent ileorectal anastomosis. In addition, 5 gastric cancer, 2 duodenal cancer, 1 gallbladder cancer, and 1 thyroid cancer cases were diagnosed. The age at which the extracolonic malignancies were diagnosed was >50 years. 4 patients died due to metachronous rectal cancer, gastric cancer, or gallbladder cancer.

CONCLUSION

Careful consideration should be paid before choosing ileorectal anastomosis as the treatment procedure for familial adenomatous polyposis patients because completion proctectomy was eventually necessary for half of the patients. Long-term surveillance, with more frequent gastric surveillance for patients over 50 years, is important for the prevention and treatment of extracolonic malignancies in familial adenomatous polyposis patients.

Complex APC germline mutation associated metaplasia and intraepithelial neoplasia (CAM-IEN) of the gallbladder

Preneoplasic and neoplastic changes of the gallbladder of patients with a familial adenomatous polyposis (FAP) are rare, and very little is known about their incidence in patients with an attenuated FAP. We herein report on a unique case of a woman with an attenuated FAP who shows eight distinct, partially preneoplastic differentiation patterns within the gallbladder mucosa, which are: (1) regular gallbladder epithelium, (2) low grade biliary intraepithelial neoplasia, (3) papillary adenoma, (4) Paneth cell metaplasia, (5) goblet cell metaplasia, (6) pancreatic metaplasia, (7) pseudopyloric metaplasia, and (8) neuroendocrine differentiation. Moreover, this is the first case of a KRAS mutation in a gallbladder adenoma of a patient with an APC germline mutation, which is highly suggestive of an early event of malignant transformation. As a consequence of our findings, clinicians should draw special attention to the gallbladder of FAP patients, and a simultaneous protective cholecystectomy of FAP patients, which undergo colectomy and show conspicuous changes of the gallbladder mucosa, should be performed in these patients in order to eliminate the risk of a synchronous or metachronous gallbladder neoplasia.

Unicryptal gallbladder adenomas in a patient with Gardner's syndrome

Gardner's syndrome occurs when mutation of the adenomatous polyposis coli gene is associated with extra-intestinal manifestations in addition to colorectal adenomas. Only eleven cases of gallbladder adenoma in Gardner's syndrome have been previously reported in the literature. We report a case of Gardner's syndrome in which multiple adenomas are associated with unicryptal adenomas. The lesion showed cytoplasmic and nuclear expression of β-catenin. The identification of multiple fully formed and unicryptal adenomas in the gallbladder are suggestive of Gardner's syndrome, and these patients require further investigation and follow up.

Familial adenomatous polyposis and the small bowel: a loco-regional review and current management strategies

Small-bowel tumours are an important cause of morbidity and death in patients with familial adenomatous polyposis. Intensive endoscopic surveillance is now standard in the long-term management of this condition. Thus, lesions occurring throughout the small bowel are increasingly noted by oesophagogastroduodenoscopy and flexible pouchoscopy. Some occur commonly de novo (in stomach, duodenum and ampulla), while others may occur following surgery (polyps of the ileostomy, ileoanal pouch, or small bowel above an anastomosis). These differ widely in incidence, natural history and management. This review provides a regional overview of these lesions, in terms of current research findings and management protocols.

[Adenomatous polyposis of the gallbladder and Gardner's syndrome. A rare association]

We report one case of adenomatous polyposis of the gallbladder in a 57 year-old woman with Gardner's syndrome presenting with cholangitis. On gross examination the gallbladder contained two calculi and numerous flat or polypoid adenomas less than 1 cm in size. On microscopic examination, the adenomas showed low and high grade intraepithelial neoplasia. Only 10 cases of gallbladder adenomas have been reported in the literature in patients presenting with familial adenomatous polyposis (FAP). Cholecystectomy is usually performed for cholecystitis or cholangitis. These adenomatous gallbladder lesions are discovered late, often when the patient is older than 40. Pathogenesis of gallbladder adenomas is still unclear. It is difficult to assess the risk of malignancy: only 6 cases of gallbladder adenocarcinomas have been reported in patients with FAP.

Immunohistochemical and genetic analysis of non-small cell and small cell gallbladder carcinoma and their precursor lesions

Gallbladder carcinomas can be highly lethal neoplasms. Relatively little is known about the genetic abnormalities that underlie these tumors, particularly with respect to their timing in neoplastic progression. The authors evaluated 5 noninvasive dysplasias and 33 invasive gallbladder carcinomas (6 small cell carcinomas, 27 non-small cell carcinomas, of which 16 were accompanied by an in situ carcinoma component) for expression of the protein products of the p16, p53, Dpc4, and pRB tumor suppressor genes by immunohistochemistry. Neoplasms were also evaluated for the presence of activating K-ras oncogene mutations. Seventy-five percent of non-small cell gallbladder carcinomas demonstrated loss of p16 expression, whereas 63% accumulated high levels of p53. Loss of Dpc4 and pRB expression was less frequent, seen in 19% and 4% of the neoplasms, respectively. Thirty percent of neoplasms harbored activating K-ras mutations. In contrast, 100% of the small cell carcinomas of the gallbladder demonstrated inactivation of the pRB/p16 pathway; 67% showed loss of pRB expression, and the other 33% lost p16 expression. Eighty-three percent of small cell carcinomas accumulated high levels of p53, whereas loss of Dpc4 expression and activating K-ras mutations were not found. Among 15 evaluable in situ components, 13 harbored the same alterations found in the invasive component. Inactivation of p16 and p53 occur in the majority of non-small cell gallbladder carcinomas. Dpc4 inactivation and K-ras mutations occur in a significant minority of cases. pRB loss is uncommon in non-small cell gallbladder carcinoma, but virtually all small cell carcinomas inactivate the p16/pRB pathway, usually by retinoblastoma protein loss. It is noteworthy that all of these alterations occur at the level of carcinoma in situ.

Germline and somatic mutations in exon 15 of the APC gene and K-ras mutations in duodenal adenomas in patients with familial adenomatous polyposis

BACKGROUND

In sporadic colorectal adenomas mutations in the adenomatous polyposis gene (APC) are among the first gene aberrations to appear. In familial adenomatous polyposis (FAP) the patients already have a germline mutation in the APC gene. To investigate the natural history of duodenal adenomas in FAP patients, we examined germline and somatic mutations of the APC gene and K-ras mutations in these lesions.

METHODS

Frozen sections from 54 duodenal polyps from 31 FAP patients were used to histologically verify the presence of adenomatous growth in the mucosa; the rest of each biopsy specimen was processed for DNA extraction. APC exon 15 was investigated with the protein truncation test (PTT), using four overlapping polymerase chain reaction (PCR) fragments, and samples showing an APC mutation were thereafter sequenced. The adenomas were examined for K-ras mutations by use of a combination of the 'enriched PCR method' and temporal temperature gradient electrophoresis.

RESULTS

APC germline mutations in exon 15 were found in 19 of 31 (61%) patients, whereas somatic mutations were localized to 12 of 54 (22%) duodenal adenomas. In seven adenomas both the germline and the somatic mutations were found, whereas five small adenomas showed somatic mutations only. There was no tendency for more mutations to be detected in large and severely dysplastic adenomas compared with small and mildly dysplastic ones. K-ras mutations were found in four (7%) duodenal adenomas.

CONCLUSIONS

The low rate of somatic APC and K-ras mutations in duodenal adenomas may indicate another neoplastic pathway than in FAP adenomas of the large bowel, or that a modifier gene is cosegregating with the disease.

Upper gastrointestinal disease in patients with familial adenomatous polyposis

BACKGROUND

Upper gastrointestinal disease has become an important aspect in the management of patients with familial adenomatous polyposis (FAP).

METHODS

A review of the literature was carried out using Medline. Epidemiology, pathology and treatment options are considered.

RESULTS AND CONCLUSION

Despite the fact that over 90 per cent of patients with FAP develop duodenal adenomas, only 5 per cent go on to develop cancer. In the absence of methods to detect who is at risk of cancer, all patients undergo regular endoscopic surveillance at present. Chemoprevention in the form of drug therapy may be the answer to controlling the disease.