Does ampullary carcinoma arise from distended glands in the papilla of Vater?

Background/Purpose

Glands near the surface of the papilla of Vater may become distended with mucus and become hyperplastic; that is, become distended. In this study, we tried to clarify carcinogenesis in these distended glands.

Methods

Twenty-nine pancreatoduodenectomized nontumorous duodenal papilla specimens from carcinoma of the pancreas and bile duct and 34 resected ampullary carcinoma specimens were studied histopathologically and immunohistochemically, using cytokeratins and mucin immunohistochemical features/phenotypes.

Results

Distended glands were found in 11 of the 29 pancreatoduodenectomized specimens. These glands were immunopositive for cytokeratin (CK) 7 and MUC-5AC Glycoprotein (MUC5AC), but not for CK20, while the intrapapillary portion was CK7-positive and CK20-negative, but mostly negative for MUC5AC. Immunopositivity for CK7, CK20, and MUC5AC was found in 25, 21, and 18 of the 34 specimens of ampullary carcinoma, respectively. In 23 of the 34 specimens, immunoreactivity for MUC5AC and that for CK7 was coincident, that is, when the former was immunopositive, so was the latter, and vice versa, while in 25 of the 34 specimens, immunoreactivity for MUC5AC was opposite to that for CK20. Among the 23 cases in which immunoreactivity for MUC5AC and CK7 was coincident, 10 were MUC5AC+, CK7+, CK20? and 7 were MUC5AC?, CK7?, CK20+, suggestive of disease arising from the pancreaticobiliary mucosa or the distended glands in the former and disease arising from the duodenal mucosa in the latter. In MUC5AC+ cases, other than the 10 cases of MUC5AC+, CK7+, CK20?, 6 were double-positive and 1 was double-negative for CK7 and CK20, and 1 was CK20-positive, and at least 1 case showing double-negativity for CK7 and CK20 was suggestive of disease arising from the distended glands.

Conclusions

Although most ampullary carcinomas arise from the duodenal mucosa or intra-ampullary mucosa, both CK7-positive and MUC5AC-positive or only MUC5ACpositive ampullary carcinomas may arise from the distended glands.

     

Neoplastic diseases of the papilla of Vater

Although it is quite small, the papilla of Vater is an important part of the body. Carcinoma of the papilla may be one of the smallest cancers that can cause death. The 5-year survival rate after resection was 51%, which is not satisfactory. In this article, the topics discussed are (1) pathogenesis, (2) histological characteristics, and (3) the molecular biological characteristics of carcinoma of the papilla of Vater. From results obtained by the investigation of 576 autopsied and 51 resected cases, atypical epithelium was found most frequently in the common channel, where pancreatic juice and bile mix physiologically. Atypical epithelia may be a precursor of carcinoma of the papilla of Vater. Carcinoma of the papilla of Vater could be classified into two types histologically, an intestinal type and a pancreaticobiliary type. The prognosis of patients with the intestinal type was much better than that of patients with the pancreaticobiliary type. These two types of carcinoma should be treated by different operative procedures or adjuvant therapies. Regarding the molecular biological characteristics of carcinoma of the papilla of Vater; (1) K-ras mutation is mainly associated with the intestinal type, and carcinomas of the intestinal and pancreaticobiliary types may develop via different mechanisms; (2) p53 overexpression may play a role in tumor ulceration; and (3) p21/Waf1 overexpression was significantly correlated with a poor prognosis.     

Adenoma and Carcinoma of the Duodenum and Papilla of Vater: A Clinicopathologic Study

In a retrospective study (1982-1990), 12 adenomas, 35 carcinomas of the papilla of Vater, and 21 duodenal adenomas were examined. All patients had endoscopicbioptic examinations (5-10 forceps biopsies, snare biopsy or forceps-biopsies after endoscopic sphincterotomy). Special attention was paid to malignant transformation of adenomas and of residual adenomatous tissue in surgical resected cancer. Follow-up data were gained by reexamination or questionnaires. In papillary adenomas, an adenocarcinoma was found in 30% at operation or by follow-up. In 41.2% of the operated cases, residual adenomatous tissue was found, more often in well-differentiated adenocarcinomas than in other histological types. A transformation from duodenal adenomas to adenocarcinomas was seen less frequently (9.5%). Therefore, the risk of malignancy in ampullary adenomas is greater than elsewhere in the duodenum. In eight of 11 patients (72.7%) with duodenal adenomas, one or more simultaneously developed colonic adenomas were found (in four cases a Gardner syndrome not known before). We conclude that there is strong evidence that most ampullary and duodenal carcinomas develop in preexisting adenomas, with an adenoma-cancer sequence similar to that accepted for colorectal carcinoma. This has to be kept in mind for diagnostic as well as therapeutic reasons. When either an adenoma of the ampulla or duodenum is diagnosed, colonoscopy is mandatory to find or exclude colonic adenomas. In patients with familiar adenomatosis, the duodenum and the papilla of Vater have to be examined endoscopically.     

A collision tumor composed of cancers of the bile duct and ampulla of Vater--immunohistochemical analysis of a rare entity of double cancer

Collision cancer of the bile duct and the papilla of Vater is an extremely rare entity. This is the first report of a case of bile duct collision cancer. A 75-year-old man presented with jaundice. Computed tomography showed isodensity masses in the middle bile duct and the papilla of Vater. Magnetic resonance cholangiopancreatography showed a tuberous filling defect in the middle bile duct. Gastroduodenal endoscopy showed a tumor with ulceration at the papilla of Vater. The patient was diagnosed with cancers of the middle bile duct and the papilla of Vater, and a pylorus-preserving pancreatoduodenectomy was performed. On pathological examination, the tumor in the middle bile duct showed a well differentiated carcinoma that had spread to the proximal bile duct, whereas the tumor in the papilla of Vater showed a papillo-tubular carcinoma with a marked production of mucin, suggesting an intestinal type of ampullary cancer. These tumors were directly communicated by microscopic findings. Therefore, the immunohistochemical characteristics were analyzed, using several antibodies, to determine whether the origins of the 2 cancers were different or not. As a result, it was concluded that this was a case of collision cancer of the middle bile duct and the papilla of Vater.     

Total papillectomy for borderline malignant tumor of papilla of Vater

The therapies for treating tumors of the papilla of Vater remain controversial because accurate preoperative diagnosis is difficult. Treatments include endoscopic resection, pancreaticoduodenectomy and total papillectomy. We report the case of a 69-year-old man who underwent total papillectomy for a borderline malignant tumor of the papilla of Vater. In our institution, the decision to perform a total papillectomy for borderline malignant adenoma is based on whether it is intestinal type or pancreaticobiliary type. Carcinoma of the papilla of Vater is classified into two types: an intestinal type and a pancreaticobiliary type and the prognosis of the intestinal type is much better than that of the pancreaticobiliary type. We suggest that total papillectomy can be performed for an intestinal, borderline malignant tumor.     

Adenoma and tiny carcinoma in adenoma of the papilla of Vater--p53 and PCNA.

BACKGROUND/AIMS: Adenomas develop only rarely in the small bowel mucosa. We particularly tried to clarify the histologic change in atypia of ampullary adenomas which are not familial polyposis. METHODOLOGY: Four adenomas, 4 adenocarcinomas, and 4 normal mucosal regions of the ampulla of Vater were investigated in this study. All cases were characterized in paraffin sections for the presence of p53 protein using the anti-p53 monoclonal antibody (DO7, Dako Corp., Glostrup, Denmark) and proliferating cell nuclear antigen using the anti-PCNA antibody (PC 10, Dako A/S, Copenhagen, Denmark). To obtain the percentages (labeling index) of PCNA, a dual wavelength imaging microdensitometer (CAS 200, Elmhurst, IL) was used. RESULTS: Transition of adenoma into adenocarcinoma was recognized in 2 of 4 cases. Labeling index of PCNA was 12.2% in normal mucosa, 41.3% in adenomas, and 66.0% in adenocarcinoma, respectively. In 2 cases with carcinoma in adenoma, labeling index was higher in carcinomatous lesion than in adenomatous lesion. p53 Protein was positive in all cases of adenocarcinoma of the ampulla of Vater, and not in any case of normal mucosa or adenoma. CONCLUSIONS: The adenoma-carcinoma sequence was morphologically recognized especially in tiny carcinoma in adenoma of the papilla of Vater. Both p53 mutation and high proliferative activity play important roles for the histogenesis of invasive adenocarcinoma.     

p53 and p21/Waf1 protein expression and K-ras codon 12 mutation in carcinoma of the papilla of Vater

OBJECTIVE: There have been few studies on the molecular biological characteristics of carcinoma of the papilla of Vater. In this study, p53 and p21/Waf1 expression and K-ras codon 12 mutation in carcinoma of the papilla of Vater were investigated. METHODS: Thirty-seven cases of carcinoma of the papilla of Vater were studied. Macroscopically, the carcinoma was ulcerative in 15 cases and nonulcerative in 22 cases. Histologically, nine were intestinal type, 27 were pancreaticobiliary type, and one was undifferentiated. Formalin-fixed, paraffin-embedded sections were immunohistochemically stained for p53 and p21. K-ras codon 12 mutation was detected with the two-step polymerase chain reaction-restriction fragment length polymorphism method, followed by direct sequencing. RESULTS: p53 overexpression was found in 17 of 37 cases (46%) and was more frequent in the ulcerative type than in the nonulcerative type (67% vs 32%, p < 0.05). p21/Waf1 protein expression was found in 15 of 37 cases (41%), and was not correlated with that of p53. K-ras codon 12 mutation was found in 14 of 37 cases (38%), and was more frequently detected in the intestinal type than in the pancreaticobiliary type (66% vs 30%, p < 0.05). On direct sequencing, the mutations were mainly GGT to GAT (9/14) and GGT to GTT (4/14). The type of mutation did not correlate with the histological type. CONCLUSIONS: In carcinoma of the papilla of Vater, p53 overexpression may play a role in tumor ulceration. p21/Waf1 expression is induced via a p53-independent pathway. Carcinomas of the intestinal and pancreaticobiliary types may develop via different mechanisms, and K-ras mutation is mainly associated with the intestinal type.     

Expression of MUC2 in gastric carcinomas and background mucosae

BACKGROUND AND AIM: Gastric carcinomas contain elements of both intestinal and diffuse types. Such heterogeneous components may distort the evaluation of the role of the mucin MUC2 in gastric carcinoma. The role of MUC2 expression in background mucosa is not yet clarified. METHODS: We analyzed the expression of MUC2 in gastric mucosa and intestinal metaplasia adjacent to the tumoral area and carcinomas (n = 98) using immunohistochemistry. The immunoreactivity was quantified using an immunohistochemical scoring system. RESULTS: In the intestinal metaplasia adjacent to the tumoral area, MUC2 was detected in 76 (97.4%) of 78 intestinal metaplasia, and MUC2 expression was inversely associated with the depth of wall penetration (P = 0.026) and tumor stage (P = 0.021). Although the expression rate of MUC2 antigens was higher in intestinal-type adenocarcinoma than in diffuse-type adenocarcinoma, a significant correlation with pathologic staging of the TNM system (pTNM staging) and MUC2 expression could not be found in each subtype of gastric carcinomas. CONCLUSION: The expression of MUC2 in intestinal metaplasia was higher in tumors of earlier stages. These findings suggest that increased MUC2 expression in intestinal metaplasia in the neighborhood of the carcinomas may play an important role in gastric carcinomas. Further investigations regarding the role of MUC2 expression in gastric carcinoma and background mucosae are necessary.     

A case of ampullary cancer with pancreas divisum treated by endoscopic papillectomy

A 60's man underwent a medical check-up and esophagogastroduodenoscopy revealed an exposed-type tumor at the ampulla of Vater. Endoscopic ultrasonography and intraductal ultrasonography showed a hypoechoic mass limited to the ampulla of Vater. Endoscopic retrograde cholangiopancreatography (ERCP) revealed a slightly dilated ventral pancreatic duct not connected to the dorsal duct. Endoscopic papillectomy was performed without pancreatic stent placement and his postprocedural course was uneventful. The specimen was histologically diagnosed as well-differentiated adenocarcinoma limited to the mucosa of the ampulla of Vater. Endoscopic papillectomy without pancreatic stent placement can be performed without a risk of post-ERCP pancreatitis for ampullary tumor limited to the mucosa of the ampulla of Vater associated with pancreas divisum.     

A case report of papilla Vater carcinoma showing positive expression of thymidine phosphorylase

Recently, we experienced an interesting case of papilla Vater carcinoma. The patient was a 61-year-old woman, who was referred to our department from a private hospital with a chief complaint of high fever. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed an anomalous arrangement of the pancreaticobiliary duct without a common channel and a tumor, which was detected on the papilla Vater and diagnosed as well-differentiated adenocarcinoma. Pylorus-preserving pancreaticoduodenectomy with lymph node dissection was performed. The immunohistochemical stain showed the strong expression of thymidine phosphorylase in the tumor tissue and also in the normal biliary tract, despite positive p53 cells being undetected in either tumor tissue or epithelium of biliary tract. These findings may suggest important indications to consider some mechanisms of carcinogenesis in the biliary tract.     

Long-term survival with carcinoma arising from a congenital choledochal cyst

We report a case of 11-year survival with carcinoma arising from a congenital choledochal cyst. A 34-year-old Japanese woman was admitted due to epigastric discomfort. Ultrasonography revealed a choledochal cyst involving a polypoid tumor. Endoscopic retrograde cholangiopancreatography revealed pancreaticobiliary maljunction in which the main pancreatic duct joined the dilated common bile duct 2 cm above the papilla of Vater. A choledochal cyst containing a polypoid tumor was resected with the regional lymph nodes. Grossly, a 2×2-cm papillary tumor was noted in the posterior wall of the choledochal cyst. Microscopically, the tumor was well-differentiated tubular adenocarcinoma invading the mucosa and fibromuscular layer. Neither anticancer chemotherapy nor radiotherapy was performed. The patient recovered uneventfully after the operation and has been well for 11 years without evidence of recurrent cancer. The good results in this patient may have been due to the early stage of the cancer.     

A case of early carcinoma of the papilla of Vater confined to the mucosa and continuative epithelium of glands in Oddi's sphincter (m-God) treated by endoscopic papillectomy

We herein report a case of early stage ampullary cancer, treated by endoscopic papillectomy, in which tumor extension was confined to the mucosa and adjacent epithelium of the glands in Oddi's sphincter. A 77-year-old man underwent screening esophagogastroduodenoscopy, which revealed a mass in the papilla of Vater, which was well-differentiated adenocarcinoma as proven by biopsy. The tumor was diagnosed as T1 and endoscopic papillectomy was performed. Histological examination showed adenocarcinoma limited to the mucosa of the common channel and continuative epithelium of the neighboring glands in Oddi's sphincter. No signs of recurrence have been observed during a follow-up of 23 months.     

Metachronous double cancer of the gallbladder and pancreas associated with pancreaticobiliary maljunction

A 50-year-old Japanese woman complained of abdominal and back pain. Ten years previously she had undergone cholecystectomy, choledochectomy, and Roux-en-Y choledochojejunostomy for gallbladder cancer associated with pancreaticobiliary maljunction without bile duct dilatation. On the present admission, ultrasonography (US) and computed tomography (CT) demonstrated a large mass, 60 mm in size, in the pancreatic tail. Endoscopic retrograde cholangiopancreatography (ERCP) showed obstruction of the main pancreatic duct in the tail of the pancreas and revealed that the pancreatic duct was joined to the bile duct 25 mm above the papilla of Vater. The patient underwent distal pancreatectomy, splenectomy, left adrenalectomy, and partial gastrectomy. Histological examination revealed moderately differentiated ductal adenocarcinoma that had invaded to the proper muscle of the stomach. Double cancer of the gallbladder and pancreas in a patient with pancreaticobiliary maljunction is rare. Although the etiology of cancer of the pancreas associated with pancreaticobiliary maljunction is unclear, we should pay close attention to the pancreas as well as the biliary tract during the long-term follow-up of patients with pancreaticobiliary maljunction after they have undergone a choledochojejunostomy.     

Surgical technique for complete resection of the extrahepatic portion of the common bile duct and the ampulla of Vater for tumors of the ampulla of Vater

Background

Ampullary tumors have to be completely resected, but substantial morbidity and mortality rates are associated with pancreaticoduodenectomy (PD). Local resection can be the procedure of choice in selected ampullary lesions for high-risk patients.

Methods

Preoperative examination indicated that the ampullary tumor extended into the common bile duct without evidence of pancreatic duct involvement and no definite invasion into either the duodenum or the pancreas. We performed a complete resection of the extrahepatic bile duct and the ampulla of Vater, including the tumor, without performing PD by dissecting the intrapancreatic bile duct from the pancreas both downward towards the ampulla of Vater and upward using a transduodenal approach.

Results

The operation was successfully completed, and the postoperative course was uneventful, with the exception of a minor pancreatic fistula from retropancreatic dissection. The final pathological examination demonstrated well-differentiated tubular adenocarcinoma limited to the mucosa with negative surgical margins.

Conclusion

Complete resection of the extrahepatic bile duct and the ampulla of Vater through a transduodenal approach can be a feasible and safe surgical procedure for selected ampullary tumors in high-risk patients.     

A long-term surviving patient with cancer of papilla of Vater after local resection

We report successful local resection for cancer of papilla of Vater in an 86-year-old woman. She was referred to our hospital because of right hypochondralgia. Abdominal ultrasonography and computed tomography showed marked dilatation of the common bile duct (CBD). Endoscopic retrograde cholangiography disclosed a small shadow defect in the terminal of the dilated CBD. Biopsy of the papilla revealed well-to-moderately differentiated adenocarcinoma. Considering her extreme old age and keeping in mind her quality of life after the operation, and the finding that the tumor was localized within the papilla and highly differentiated, we performed local resection. In addition, the intrapancreatic portion of the CBD and part of the main pancreatic duct (MPD) were further resected to secure a negative margin, confirmed by frozen section. The MPD was reapproximated to the duodenal mucosa and a choledocho-duodenostomy was performed for CBD reconstruction. Histopathological examination showed the tumor was papillary adenocarcinoma, 10 × 15 mm in size; there was no invasion beyond the sphincter of Oddi, it had partly infiltrated the CBD, but had not invaded to the pancreas or duodenum. The patient's postoperative course was not eventful and she has had good quality of life for the past 6 years since the operation, without any evidence of recurrence. Although radical pancreaticoduodenectomy is now the standard procedure in patients with malignant tumor of the papilla of Vater, local resection is a reasonable alternative for high-risk patients with highly differentiated, apparently localized carcinomas.     

A Case of Early Gallbladder Carcinoma Associated with the Anomalous Union of the Pancreaticobiliary Ductal System

Abstract: A 68 year-old woman was admitted to our hospital with a high fever. Ultrasonography revealed the presence of two protruded mass lesions in the fundus of the gallbladder. Endoscopic retrograde choledochopancreatography (ERCP) indicated an anomalous union of the pancreaticobiliary ductal system (AUPD), with an anomalous junction heated at the site 30 mm proximal to the ampulla of Vater. ERCP also showed the presence of three flat elevated lesions at the fundus of the gallbladder. Amylase activity in the bile obtained from the common bile duct during ERCP was high. From these findings, gallbladder carcinoma associated with AUPD was suspected. Cholecystectomy, choledochectomy followed by hepaticojejunostomy were performed on this patient. A microscopic study of the resected gallbladder demonstrated adenocarcinoma with epithelia like intestinal metaplasia in those elevated lesions surrounded by mucosa associated with atypical hyperplasia without intestinal metaplasia. The authors believe that intestinal metaplasia is the main change accompanied by the cancer, but atypical hyperplasia was an important pre-cancerous lesion in this case.     

Clinicopathologic features of ampullary carcinoma without jaundice

GOALS: To evaluate clinicopathological features of ampullary carcinoma without jaundice. BACKGROUND:: Obstructive jaundice is the most common symptom of patients with ampullary carcinoma. However, some patients with ampullary carcinoma do not have jaundice at the time of diagnosis. STUDY: Clinicopathologic findings of 23 patients with ampullary carcinoma showing no visible jaundice (serum total bilirubin <3.0 mg/dL) and 38 patients with ampullary carcinoma showing jaundice at the time of diagnosis were retrospectively compared. RESULTS: Fifteen of 23 patients with nonjaundiced ampullary carcinoma complained of fever and/or abdominal pain. Five asymptomatic patients were found to have a dilated bile duct on screening ultrasound or to have a tumor-like swelling of the papilla of Vater during routine upper gastrointestinal endoscopy. There was no significant difference in age, sex, size, macroscopic type, histologic type, rates of duodenal invasion, pancreatic invasion, and lymph node metastasis, and prognosis between the two groups. The cumulative 5-year and 10-year survival rates of nonjaundiced patients were 70.2% and 49.0%, compared with 33.6% and 29.4% of jaundiced patients. Ten of the 23 nonjaundiced ampullary carcinomas (43%) were in Stage I, whereas 4 of the 38 jaundiced ampullary carcinomas (11%) were in Stage I (P < 0.01). Mechanisms of nonjaundice in ampullary carcinoma were suspected to be determinant by the infiltrating pattern of the carcinoma to the lower portion of the bile duct. CONCLUSIONS: Mechanisms of nonjaundice in ampullary carcinoma might be determined by the infiltrating pattern of the carcinoma to the lower portion of the bile. As a greater number of nonjaundiced ampullary carcinomas were in an early stage, detection of them may provide an improved clinical outcome.     

Frequency of colorectal polyps in patients with sporadic adenomas or adenocarcinomas of the papilla of vater--an age-matched, controlled study

BACKGROUND: Epithelial tumors of the papilla of Vater are rare neoplasms of the gastrointestinal tract. The carcinogenesis of these tumors seems to be fairly analogous to the genetic mechanisms which have been described for colorectal carcinoma. Patients with familial adenomatous polyposis bear a particularly increased risk for periampullary tumors. Data on whether the prevalence of colorectal tumors is increased in patients with sporadic ampullary neoplasms are scarce. METHODS: 26 consecutive patients (16 women, 10 men; median age 59 years) with sporadic adenomas (n = 19) or adenocarcinomas (n = 7) of the ampulla of Vater were retrospectively evaluated. The study patients were compared with 104 age-matched asymptomatic controls. All patients had undergone total colonoscopy. RESULTS: Neoplastic colorectal polyps were present in a similar proportion (23%) of patients of the study group compared with 26% in the control group (p > 0.05). Overall, 16 polyps were found among patients with ampullary tumors and 40 in asymptomatic controls (p > 0.05). Colonoscopy detected rectal carcinoma in 2 patients (8%) of the study group. Patients with and without colorectal polyps differed neither significantly by age nor by ampullary histological findings. 50% of the colonic polyps in patients with ampullary neoplasms were located in the ascending colon. CONCLUSIONS: The frequency of colorectal polyps in patients with ampullary tumors did not exceed the risk in the control group. However, the finding of 2 rectal carcinomas among patients with ampullary neoplasms supports the place of screening colonoscopy for the diagnostic work-up of ampullary tumors. Prospective multicenter studies should address this issue to provide a broad basis for future recommendations.     

The clinicopathologic and immunohistochemical characteristics of ampulla of Vater carcinoma: the intestinal type is associated with a better prognosis

BACKGROUND/AIMS: We wanted to compare the clinicopathological parameters with the immunohistochemical expression patterns and patient survival for the intestinal type (IT) and the pancreatobiliary type (PT) of ampulla of Vater carcinoma. Ampulla of Vater carcinoma can be classified histologically into either IT or PT. The biologic behavior and patient prognosis vary considerably in relation to the tumor type. METHODOLOGY: From September, 1995, to February, 2004, 34 patients with the pathologic diagnosis of ampulla of Vater carcinoma were retrospectively reviewed and the prognostic factors were analyzed. To classify the phenotypes of the tumors, the keratin types (CK7 and CK20), the type of apomucin of the mucosa (MUC2), and the glucose transporter (GLUT1) were studied for differentiating the tumor types. RESULTS: The 5-year survival rate of the 34 patients with ampulla of Vater carcinoma was 58.8%. Histologically, 12 patients had IT and 22 had PT, and the IT patients all survived. The long-term survival after resection of the tumor was significantly greater for the patients with IT than for the patients with PT. Although these differences were not statistically significant, the prognosis of IT group seemed more favorable (p = 0.0955). On the immunohistochemical staining, MUC2 (p < 0.0001), CK20 (p = 0.0002) and CK7 (p = 0.0368) were statistically effective, but not GLUT1, for differentiating IT from PT. CONCLUSIONS: For the classification of the tumor phenotypes, performing immunohistochemical staining were helpful to differentiate the two types of tumor. A study with a larger number samples would probably elucidate the different clinical course between these two types of ampulla of Vater carcinoma.     

Coexistence of small cell neuroendocrine carcinoma and villous adenoma in the ampulla of Vater

Small cell neuroendocrine carcinoma of the ampulla of Vater is extremely rare and different from the common ampullary adenocarcinoma. The ampullary adenoma is also a rare neoplasm and has the potential to develop an adenocarcinoma. Their coexistence has been rarely reported in the literature. We herein describe an unusual case of a small cell neuroendocrine carcinoma associated with a villous adenoma in the ampulla of Vater with emphasis on computed tomography （CT） and histopathological findings. We also discuss their clinical, histopathological and radiological features as well as possible histogenesis.