Duodenal and peri-ampullary adenomas

Neoplasms of the ampulla of vater with concurrent pancreatic intraductal neoplasia: a histological and molecular study

Adenoma and adenocarcinoma of the ampulla of Vater are uncommon neoplasms of the gastrointestinal tract. Only one report has analyzed the relationship between ampullary adenocarcinoma and pancreatic intraductal neoplasia (PanIN), the precursor lesion of pancreatic adenocarcinoma. An association between PanIN and ampullary adenoma has not been reported previously. Case reports have documented the progression of PanIN to invasive pancreatic adenocarcinoma. We reviewed five resected ampullary adenoma and 17 ampullary adenocarcinoma cases and evaluated the pancreas for PanIN. Pancreatic sections from 35 autopsies were reviewed as a control group. Immunohistochemistry for overexpression of p53 and COX-2 proteins was performed in selected cases, as was PCR analysis for K-ras mutations. Follow-up clinical data were obtained. All 22 ampullary neoplasms were associated with PanIN, which was high grade in two (40%) adenoma cases and seven (41%) adenocarcinoma cases. In 16 (73%) evaluable cases, PanIN extended to the pancreatic resection margin; two of which had high grade PanIN. Among the autopsy controls eight (23%) had low-grade PanIN. Seven of the 22 ampullary cases but none of the autopsy controls had coexistent pancreatitis. A smoking history was present in two of four autopsy cases in which this history was available. Overexpression of the p53 and COX-2 proteins was present in only one case of high-grade PanIN. K-ras mutations were present in four of four of the PanIN lesions evaluated, including one autopsy case. Clinical follow-up revealed no progression of PanIN to invasive carcinoma in the remnant pancreas, although the follow-up period was too short to adequately assess that risk (an average of 3.8 y for adenoma cases and 2.5 y for adenocarcinoma cases). We conclude that adenomas and carcinomas of the ampulla are associated with PanIN, and often high-grade PanIN. Although its malignant potential has not been fully established, PanIN is underreported and often unrecognized. PanIN may be analogous to colorectal adenoma in that both are prevalent in the older adult population, but few progress to carcinoma.

Adenoma-carcinoma sequence in the papilla of Vater

BACKGROUND

Our aims were to investigate the question as to whether the adenoma-carcinoma sequence also applies to the papilla of Vater and to determine the frequency with which a tumour of the papilla of Vater, diagnosed histologically as containing portions of an adenoma, already contains adenocarcinoma elsewhere.

METHODS

A retrospective analysis was carried out of the forceps, snare biopsy, and excised specimens obtained from the papilla of Vater in 559 patients, including 210 patients with the primary diagnosis of carcinoma and 110 patients with the diagnosis of 'portions of an adenoma'. Comparisons were made of the age distribution of patients with adenoma and those with carcinoma, and the frequency of residual adenoma in a carcinoma as a function of degree of malignancy, T stage, and UICC stage. A follow-up examination of the patients with the primary diagnosis 'parts of an adenoma of the papilla of Vater' was performed.

RESULTS

The average age of the patients with the final diagnosis adenoma was 65.2 years, and that of the carcinoma patients 73.0 years. Residual adenoma was found in 54.9% of the 51 surgical specimens and in 31.7% of the 159 biopsy specimens obtained from carcinomas. The frequency of residual adenoma in carcinomas decreased statistically significantly with increasing T stage and degree of malignancy. The follow-up examination of the 110 patients with the primary biopsy diagnosis parts of an adenoma of the papilla of Vater showed unequivocal results in 80 cases. Only in 39.7% of these cases was the primary diagnosis adenoma confirmed, whereas in 60.25%, further histologic examination showed a carcinoma.

CONCLUSIONS

An analysis of our results, together with those reported in the literature, indicates that the adenoma-carcinoma sequence also applies to the papilla of Vater and that, in a high percentage of patients with the histologic diagnosis 'parts of an adenoma, other regions of the tumour already contain a carcinoma.