Tumors of the ampulla of Vater

Ampullary Cancer. Surg Clin North Am. 2019;99:357-367. [PMID: 30846039 DOI: 10.1016/j.suc.2018.12.001]

Compared with other periampullary tumors, cancers of the ampulla of Vater are rare. These tumors tend to present earlier than their pancreatic and distal bile duct brethren. In addition to the hypothesis that they are also less biologically aggressive, ampullary cancers tend to have better survival than other types of periampullary cancers. The mortality from this disease remains high, and much can still be learned about ampullary cancers.

Periampullary Neuroendocrine Tumor as a Cause of Acute Pancreatitis

Patient: Male, 60

Final Diagnosis: Periampullary neuroendocrine tumor

Symptoms: Abdominal discomfort

Medication: —

Clinical Procedure: —

Specialty: Surgery

Usefulness of white-light imaging-guided narrow-band imaging for the differential diagnosis of small ampullary lesions

BACKGROUND

Small ampullary tumors and inflammatory lesions have similar endoscopic findings and are difficult to differentiate. Narrow-band imaging (NBI) can visualize microvessels and mucosal microstructure clearly and is widely used to diagnose early gastric and colon cancer.

OBJECTIVE

To evaluate the usefulness of NBI for differentiating ampullary tumors from benign diseases.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care hospital.

PATIENTS

All 45 patients who had suspicious ampullary lesions (enlarged or protruded morphology) during duodenoscopy and underwent NBI between March 2010 and January 2011.

INTERVENTIONS

NBI.

MAIN OUTCOME MEASUREMENTS

NBI images were assessed for irregular villous arrangement, irregular villous size, ridge disappearance, demarcation with normal villi, and abnormal microvasculature. Histology of NBI-guided lesion biopsy specimens provided the final diagnoses. Agreement between NBI images and histologic findings was analyzed.

RESULTS

Of the 60 ampullary lesions, 11, 26, and 23 were adenocarcinomas, adenomas, and benign inflammatory diseases, respectively. Irregular villous arrangement, irregular villous size, ridge disappearance, demarcation with normal villi, and abnormal microvasculature were observed in 45%, 63%, 50%, 48%, and 58% of the lesions, respectively. Multivariate analysis revealed that irregular villous arrangement (odds ratio [OR] 15.76; 95% confidence interval [CI], 3.38-64.12; P < .001) and abnormal microvasculature (OR 86.63; 95% CI, 14.56-515.41; P < .001) were significant independent factors for identifying ampullary adenomas and adenocarcinoma. All tumors had at least one abnormal NBI feature.

LIMITATIONS

Retrospective design.

CONCLUSION

The NBI findings of irregular villous arrangement and/or abnormal microvasculature were useful for differentially diagnosing ampullary tumors. NBI may complement the accurate diagnosis of ampullary lesions by white-light imaging.

Advances in diagnostic endoscopy for duodenal, including ampullary, adenoma

Currently, the strategy for real-time endoscopic diagnosis of duodenal, including ampullary, adenoma is still unclear. In the era of high-definition and magnification endoscopy, using this modality for the detection and diagnosis of these neoplasms is very challenging for endoscopists. Over the past 10 years, many instruments have been developed to improve the detection rate of duodenal and ampullary polyps and to distinguish between adenoma and non-adenoma. The present review will focus on these novel methods and their usefulness in the diagnosis of ampullary and non-ampullary adenoma.

Ampullary cancer--a separate clinical entity?

AIMS

Ampullary cancer is a relatively uncommon tumour, with a better prognosis than pancreatic cancer. The purpose of this study was to review the recent literature on ampullary adenocarcinoma, focusing on histological types and prognostic factors.

METHODS AND RESULTS

Using PubMed, we carried out a comprehensive search of the literature, which was extended to April 2013 to retrieve all additional publications. Ampullary cancer comprises two main histological subtypes, the pancreatobiliary type and the intestinal type. These subtypes have different pathogenetic and clinical characteristics. Clinical and histological parameters as well as immunohistochemical markers have been identified as significant prognostic factors in ampullary cancer. Moreover, several immunohistochemical markers have been studied, not only as prognostic factors but as a means of differentiating ampullary from other peri-ampullary tumours, and of identifying the exact histological subtype.

CONCLUSIONS

The considerable differences in the frequencies of the two subtypes of ampullary tumours reported in literature reinforce the necessity to define molecular markers to distinguish them. Until then, the significance of the histological subtype as a prognostic factor should be evaluated cautiously. Future research on the pathogenesis of ampullary cancer will possibly suggest that we should stop treating this type of cancer as a separate entity.

The mucosal folds at the pancreaticobiliary junction

PURPOSE

The structure and function of the mucosal folds in the terminal bile and pancreatic ducts and hepatopancreatic ampulla are poorly characterised. The distribution, muscularity, and innervation of these folds were investigated.

METHODS

The pancreaticobiliary junction was excised from ten cadavers (five male, 66-90 years) and examined histologically by serially sectioning (4-μm thickness) along the length of the terminal bile and pancreatic ducts from the tip of the major duodenal papilla. Three surgical specimens (two male, 63-72 years) were also evaluated. Sections were stained with haematoxylin and eosin, anti-actin (smooth muscle), anti-S100 (innervation), and anti-cholecystokinin (CCK)-A receptor antibodies. ImageJ software was used to compare relative radial fold projection and semi-quantitatively assess the smooth muscle and nerve content. In one additional cadaver specimen, folds were examined by scanning electron microscopy.

RESULTS

Mucosal folds in the terminal bile duct were arranged circumferentially in a lattice-like arrangement and were distributed over an average distance of 7.3 mm along the terminal bile duct compared to 4.2 mm along the pancreatic duct (P = 0.001), projected further into the lumen, and were more densely innervated than those in the terminal pancreatic duct. Folds in both ducts contained smooth muscle which was more prominent in folds nearest to the major duodenal papilla. Mucosal folds in cadaver and surgical specimens showed no evidence of CCK-A receptor immunoreactivity.

CONCLUSIONS

This study demonstrates that the mucosal folds of the terminal bile and pancreatic ducts contain muscle and nerve fibres, suggesting an active rather than purely passive function.

Gastrointestinal hyperplasia with altered expression of DNA polymerase beta

Background

Altered expression of DNA polymerase β (Pol β) has been documented in a large percentage of human tumors. However, tumor prevalence or predisposition resulting from Pol β over-expression has not yet been evaluated in a mouse model.

Methodology/Principal Findings

We have recently developed a novel transgenic mouse model that over-expresses Pol β. These mice present with an elevated incidence of spontaneous histologic lesions, including cataracts, hyperplasia of Brunner's gland and mucosal hyperplasia in the duodenum. In addition, osteogenic tumors in mice tails, such as osteoma and osteosarcoma were detected. This is the first report of elevated tumor incidence in a mouse model of Pol β over-expression. These findings prompted an evaluation of human gastrointestinal tumors with regard to Pol β expression. We observed elevated expression of Pol β in stomach adenomas and thyroid follicular carcinomas, but reduced Pol β expression in esophageal adenocarcinomas and squamous carcinomas.

Conclusions/Significance

These data support the hypothesis that balanced and proficient base excision repair protein expression and base excision repair capacity is required for genome stability and protection from hyperplasia and tumor formation.

Differentiation of ampullary tumor from benign papillary stricture by thin-section multidetector CT

The objective of this paper was to determine the criteria for differentiation of ampullary tumor from benign papillary stricture using thin-section multidetector CT images. Multidetector CT images with 2.5 mm slice-thickness in 57 consecutive patients (24 with ampulla of Vater tumor and 33 with benign papillary stricture) with extrahepatic duct dilatation due to ampullary obstruction were reviewed retrospectively. The papilla/papillary mass was evaluated regarding size, homogeneity of enhancement, attenuation value, and the diameters of extrahepatic duct and main pancreatic duct were measured. The measurability, enhancement pattern, the attenuation value of papilla/papillary mass on portal venous phase, and the maximum diameters of extrahepatic duct and main pancreatic duct were different between two groups. Multiple logistic regression analysis showed the papilla/papillary mass size was the only independently differentiating variable of ampullary tumor from benign stricture (P = 0.016) with an odds ratio of 2.424 (95% confidence interval, 1.179-4.903). The most appropriate cutoff value of papilla/papillary mass size was 12.3 mm with 91.7% sensitivity, 92.3% specificity, and 92.0% accuracy. Ampullary tumor and benign papillary stricture could be effectively differentiated by thin-section multidetector CT based on papilla/papillary mass size.

New approach to diagnosing ampullary tumors by magnifying endoscopy combined with a narrow-band imaging system

BACKGROUND

A newly developed narrow-band imaging (NBI) system, which uses modified optical filters, can yield clear images of microvessels and surface structure in gastric and colonic diseases. In the present study, we investigated the ability of magnifying endoscopy with NBI (MENBI) to diagnose and differentiate between benign and malignant ampullary tumors.

METHODS

Fourteen patients, whose ampullas were noted to be significantly enlarged or protruding with conventional endoscopy, were enrolled in the study. Specimens, which were obtained by forceps biopsy, endoscopic papillectomy, and/or surgery, were retrieved for histopathological examination. The correlation between MENBI images and histopathological findings was investigated. MENBI findings were classified as I, oval-shaped villi; II, pinecone/leaf-shaped villi; or III, irregular/nonstructured. In addition, tortuous, dilated, and network-like vessels noted on the ampullary lesions with MENBI were defined as abnormal vessels.

RESULTS

In 6 of 14 patients, the ampullary changes were proven to be inflammatory in forceps biopsy specimens, without any evidence of malignancy after more than 1 year of follow-up. In five patients, ampullary lesions were treated by endoscopic papillectomy, and in three, by pancreatoduodenectomy. All adenomas and adenocarcinomas had type II and/or type III surface structures, and patients whose ampulla had a type I surface structure had only inflammatory or hyperplastic changes. In addition, abnormal vessels were seen only in adenocarcinomas and never in adenomas.

CONCLUSIONS

MENBI has the ability and potential to predict histological characteristics of ampullary lesions.