A rare case of neuroendocrine cell tumor mixed with a mucinous component in the ampulla of Vater.

BACKGROUND: A rare case of neuroendocrine cell tumor (NET) having both conventional and mucinous components was reported. Mucinous NET is rarely encountered in the pathological diagnosis of gastrointestinal (GI) tumors. Here we examined the mechanism for transformation of conventional NETs into mucinous NETs. CASE PRESENTATION: Macroscopic examination revealed a tumor with ulceration in the ampulla of Vater that measured 1.7 cm in its largest diameter. Histologically, the tumor comprised two components: a tubular/ribbon-like feature and small nests floating in a mucinous lake. The tumor nests showed sheet, nest and ribbon-like structures of small cells having eosinophilic cytoplasm as well as small-sized nuclei with dense hyperchromatin. Immunohistochemical analysis showed tumor cells positive for pan-endocrine markers (synaptophysin, CD56, INSM1 and chromogranin). Based on the histological findings, the solid and mucinous components were diagnosed as conventional and mucinous NETs, respectively. Grading was NET G2 based on 12.8% and 13.2% Ki-67-positive cells in the solid and mucinous components, respectively. Immunohistochemically, the mucin phenotype of this tumor was gastric and intestinal. Only the mucinous NET component had cytoplasmic CD10 expression. Examination using a customized gene panel detected only a DPC4 mutation, which was limited to the mucinous component. CONCLUSIONS: Coexistence of conventional and mucinous NETs could provide important insight into evaluating the NET subtype histogenesis. Moreover, molecular alterations including cytoplasmic expression of CD10 and the DPC4 mutation can contribute to interpretation of tumor pathogenesis.

Establishment and characterization of DPC-X4: a novel mixed-type ampullary cancer cell line.

Mixed-type ampullary cancer is a distinct subtype of ampullary cancer that manifests a merging of the biological characteristics of both intestinal and pancreaticobiliary subtypes. The absence of established cell lines specific to this subtype has resulted in a concomitant scarcity of research on its tumorigenic mechanisms and the development of novel therapeutic modalities. The present study achieved the successful establishment of a novel mixed-type ampullary cancer cell line, designated DPC-X4 through primary culture techniques. Subsequent analyses pertaining to phenotypic characteristics, molecular profiling, biomarker identification, and histological features validated the DPC-X4 cell line as a potent model for delineating the pathogenesis of mixed-type ampullary cancer and facilitating the development of new pharmacological agents. This newly established cell line was subjected to continuous cultivation for 1 year, with stable passaging for over 50 generations. Notably, the DPC-X4 cell line manifested typical morphological features associated with epithelial tumors. Furthermore, the population doubling time for the DPC-X4 cell line was determined at 70 h. Short tandem repeat (STR) analysis confirmed that the DPC-X4 cell line exhibited a high genetic concordance with the primary tumor from the patient. Karyotypic profiling indicated an abnormal sub-triploid karyotype, with representative karyotypes of 57, XXY inv (9), 14p + , 15p + , der (17), + mar. The DPC-X4 cell line demonstrated a high capacity for efficient organoid formation under suspension culture conditions. In addition, the subcutaneous inoculation of DPC-X4 cells into NXG mice led to the formation of xenografted tumors. The results of drug sensitivity testing indicated that DPC-X4 cells were sensitive to paclitaxel and resistant to oxaliplatin, 5-fluorouracil, and gemcitabine. Immunohistochemistry revealed positive expression of CK7, CK19, and CK20 in DPC-X4 cells, while CDX2 demonstrated negative expression. In addition, positive expression of E-cadherin and vimentin was identified in DPC-X4 cells, with a proliferation index indicated by Ki-67 at 70%. The findings of our study establish DPC-X4 as a novel mixed-type ampullary cancer cell line, which can serve as a potential experimental model for exploring the pathogenesis of ampullary cancer and the development of therapeutic drugs.

Mutational profiling and immunohistochemical analysis of a surgical series of ampullary carcinomas.

AIMS: Knowledge regarding the genetic features of ampullary carcinoma (AC) in European patients is limited. The utility of tumour markers for the establishment of a malignant diagnosis in biopsies from the ampullary region has not been fully elucidated. We aimed to describe the clinical, pathological, immunohistochemical (IHC) and genetic features of a Danish series of surgically resected ACs. METHODS: Surgically resected ACs (n=59) were examined regarding (1) clinicopathological features, (2) histological subtypes, (3) expression of IMP3, maspin, MUC5AC and S100P and (4) next-generation sequencing using a hybrid capture-based platform (Illumina HiSeq2500), including 315 cancer-related genes plus introns from 28 genes often rearranged or altered in cancer. Tumour mutational burden (TMB) and microsatellite instability (MSI) were also evaluated. RESULTS: Pancreatobiliary adenocarcinomas (PB-AC), intestinal adenocarcinomas (INT-AC), other ampullary tumours and mixed adenocarcinomas represented 45.8%, 23.7%, 16.9% and 13.6%. The proportion of IHC-positive ACs (score ≥2) was: Maspin (94.9%), IMP3 (67.8%), S100P (39.0%) and MUC5AC (18.6%). Most frequently altered genes were TP53 (59.3%), KRAS (40.7%), APC (27.8%), SMAD4 (20.4%), CDKN2A (16.7%) and ARID2/PIK3CA (each 11.1%). MUC5AC and S100P were frequently expressed in PB-AC, APC alterations frequent in INT-AC, SOX9 alterations were exclusive in INT-AC and MDM2 and FRS2 alterations in PB-AC. Four of 49 ACs (8.2%) were TMB-high/MSI-high and showed loss of MLH1 and PMS2. CONCLUSIONS: PB-AC was the most frequent histological subtype of AC. Maspin and IMP3 were the IHC tumour markers with the highest sensitivity. Adenocarcinoma subtypes differed regarding several genetic alterations, whose predictive value remains to be evaluated.

Neuroendocrine Tumors (NETs) of the Minor Papilla/Ampulla: Analysis of 16 Cases Underlines Homology With Major Ampulla NETs and Differences From Extra-Ampullary Duodenal NETs.

Neuroendocrine tumors (NETs) of the minor papilla/ampulla (MIPA) are rare and poorly studied. Only individual case reports and no comprehensive analysis are available from the literature. We collected 16 MIPA NETs and investigated their clinicopathologic and immunohistochemical features, including markers such as somatostatin, pancreatic polypeptide, gastrin, serotonin, MUC1, cytokeratin 7, and somatostatin receptors type 2A and 5. The median age at diagnosis was 57.5 years, and the female-to-male ratio was 2.2:1. The median NET size was 1.45 cm, and most (94%) were low-grade (G1) tumors. Similarly to what was observed in the major ampulla, 3 histotypes were found: (i) ampullary-type somatostatin-producing tumors (ASTs, 10 cases), characterized by somatostatin expression in most tumor cells, focal-to-extensive tubulo-acinar structures, often with psammoma bodies, MUC1 reactivity, and no or rare membranous reactivity for somatostatin receptor type 2A; (ii) gangliocytic paragangliomas (3 cases), characterized by the coexistence of 3 tumor cell types: epithelioid, often reactive for pancreatic polypeptide, ganglion-like cells, and S100 reactive sustentacular/stromal cells; and (iii) ordinary nonfunctioning NETs (3 cases), resembling those more commonly observed in the extra-ampullary duodenum. Comparable histotypes could also be recognized among the 30 MIPA NETs from the literature. No NET-related patient death among MIPA cases was observed during a median follow-up of 38 months; however, MIPA ASTs showed lymph node metastases and invasion of the duodenal muscularis propria or beyond in 44% and 40% of cases, respectively. In conclusion, MIPA NETs closely resemble tumors arising in the major ampulla, with predominance of ASTs.

[Combined application of immunohistochemical markers to identify pathologic subtypes of ampullary carcinoma and its clinical significance].

Objective: To investigate the expression of immunomarkers CK7, CK20, CK17, CDX2, MUC1 and MUC2 in primary adenocarcinoma of the ampulla of Vater, to explore the role of these markers in the histopathologic subclassification of ampullary carcinoma; and to provide biologic basis for precision treatment of patients with different types of ampullary carcinoma. Methods: Forty-two cases of primary ampullary carcinoma were collected at Peking University People's Hospital, from 2012 to 2018 year. There were 22 males and 20 females. Aged range 42 to 88 years old, with mean aged (62±11) years. Among the patients, 6 was high differentiation, 19 median differentiation, and 17 low differentiation. Immunohistochemical studies on the expression of CK7, CK20, CK17, CDX2, MUC1 and MUC2 were performed in 42 cases of primary ampullary carcinoma. The relationship between different ampullary carcinoma subtypes and clinicopathologic survival data was analyzed using SPSS 16.0 statistical software. Results: Three histopathologic subtypes were observed. Among 42 cases, 8(19.0%)were classified as intestinal subtype, which showed a positive expression rate of 8/8 for both CK20 and CDX2, and 5/8 for MUC2. Both CK7 and CK17 were weakly expressed in one case (1/8). No expression was observed for MUC1 in this subtype. Twenty-two (52.4%,22/42) cases were classified as pancreaticobiliary subtype, which showed a positive expression rate of 100.0%(22/22) for both CK7 and MUC1, and 90.9% (20/22) for CK17. No expression was observed for CK20, CDX2 and MUC2.The remaining 12 (28.6%) cases were classified as mixed subtype, which showed variable expression patterns. The expression frequencies of these 6 immunomarkers in different subtypes of ampullary carcinoma did not correlate with various clinicopathologic factors such as patient gender and age, tumor size, histologic differentiation, pancreatic and bile duct invasion, or the depth of duodenal invasion. However, stage Ⅲ+Ⅳ diseases were more commonly seen in pancreaticobiliary type (63.6%,14/22) than intestinal type (2/8) and mixed type (3/9; χ(2)=6.508, P=0.039). Follow-up data showed a trend of better survival rate for patients with intestinal subtype than those with mixed and pancreaticobiliary subtypes. Conclusions: Ampullary carcinoma can be subclassified into three different subtypes using a panel of six immunomarkers, especially for the identification of subtypes of poorly differentiated carcinoma. CK7, CK17 and MUC1 are major markers of pancreaticobiliary subtype, whereas CK20, CDX2 and MUC2 are useful markers for intestinal subtype. The mixed subtype variably expresses these markers. The prognosis of patients with intestinal subtype appears better than that of pancreaticobiliary and mixed subtypes. Accurate subtyping of ampullary carcinoma is clinically important to patient management and prognosis assessment.

Cutaneous Metastasis of Adenocarcinoma of the Ampulla of Vater.

Cutaneous metastases from an adenocarcinoma of the Ampulla of Vater are very rare, with only a few cases previously reported. We present here an additional case in a 57-year-old woman who complained of a painful growth on her frontal scalp that she had noticed 4 months earlier. Her medical history included an ampullary adenocarcinoma, which was diagnosed 4 years ago, excised through a Whipple procedure, and treated using chemotherapy and radiotherapy. The scalp biopsy showed a dermal and epidermotropic well-differentiated glandular neoplasm with abundant neutrophils within the luminae of the tumoral glands. The tumor failed to express p63 and cytokeratin 5/6, whereas it was intensively positive for CK7 and E-cadherin. CDX2 expression was weak and focal. The immunohistochemical expression of DNA mismatch-repair proteins (MSH2, MSH6, MLH1, and PMS2) was preserved. Despite oncological treatment, the patient developed multiple cutaneous metastases during the ensuing several months, and eventually died 6 years after her initial diagnosis with widespread metastases.

Ampullary neuroendocrine tumor diagnosed by endoscopic papillectomy in previously confirmed ampullary adenoma.

Ampullary adenoma is a common indication for endoscopic papillectomy. Ampullary neuroendocrine tumor (NET) is a rare disease for which complete surgical resection is the treatment of choice. However, because of the morbidity and mortality associated with surgical resection, endoscopic papillectomy is increasingly used in selected cases of low grade, with no metastasis and no invasion of the pancreatic or bile duct. Also, confirmed and complete endoscopic resection of ampullary NET accompanied by adenoma has not been reported to date. We report herein a rare case of an ampullary NET accompanied with adenoma, which was successfully and completely resected via endoscopic papillectomy. Prior to papillectomy, this case was diagnosed as an ampullary adenoma.

Expression and clinical significance of epidermal growth factor receptor and insulin-like growth factor receptor 1 in patients with ampullary adenocarcinoma.

Epidermal growth factor receptor (EGFR) and insulin-like growth factor receptor 1 (IGF-1R) play important roles in cell proliferation, antiapoptosis, angiogenesis, and metastasis and have been used for targeted therapies for patients with advanced colorectal and lung cancers. However, the expression and function of EGFR and IGF-1R in ampullary adenocarcinoma (AA) have not been examined in detail. We examined the expression of EGFR and IGF-1R in 106 AA patients at our institution using tissue microarrays and immunohistochemistry. The results were correlated with the clinicopathological parameters and survival. Overexpression of EGFR and IGF-1R was detected in 18 (17%) and 26 (25%) of AAs, respectively. Patients with EGFR-high tumors had shorter overall survival (mean, 109.8 ± 22.3 months) than those patients whose tumors were EGFR-low in overall study population (mean, 164.2 ± 10.6 months; P = .04). Overexpression of EGFR correlated with poor overall survival in patients with intestinal-type AA (P = .01) but not in those with pancreaticobiliary-type AAs (P = .47). In multivariate analysis, EGFR overexpression was an independent prognostic factor for overall survival (P = .02). In addition, we found that overexpression of IGF-1R correlated with AAs of pancreaticobiliary histology. No additional correlation between the expression of EGFR or IGF-1R and other clinicopathological factors was observed in our patient population. Our study demonstrates that EGFR and IGF-1R appear to be overexpressed in a subset of AAs and that strong membranous expression of EGFR is an independent predictor for overall survival in patients with AA. EGFR and IGF-1R represent potential therapeutic targets for treatment of patient with AAs.

miR-215 overexpression distinguishes ampullary carcinomas from pancreatic carcinomas.

Distinguishing ampullary carcinoma from pancreatic carcinoma is important because of their different prognoses. microRNAs are differentially expressed according to the tissue of origin. However, there is rare research on the differential diagnosis between the two types of cancers by microRNA in periampullary cancers. The present study was undertaken to compare microRNA profiles between ampullary and pancreatic carcinomas using microarrays. miR-215 was most significantly overexpressed in ampullary carcinomas; whereas the expressions of miR-134 and miR-214 were significantly lower in ampullary carcinomas than in pancreatic carcinomas. When these discriminatory microRNAs were applied to liver metastases, they were correctly predicted for the tissue of origin. Although this study is limited by small sample size, striking difference in microRNA expression and concordant expression of discriminating microRNAs in primary tumors and metastases suggest that these novel discriminatory microRNAs warrant future validation.

Sequencing of 279 cancer genes in ampullary carcinoma reveals trends relating to histologic subtypes and frequent amplification and overexpression of ERBB2 (HER2).

The biological relevance of histological subtyping of ampullary carcinoma into intestinal vs pancreaticobiliary types remains to be determined. In an effort to molecularly profile these subtypes of ampullary carcinomas, we conducted a two-phase study. In the discovery phase, we identified 18 pancreatobiliary-type ampullary carcinomas and 14 intestinal-type ampullary carcinomas using stringent pathologic criteria and performed next-generation sequencing targeting 279 cancer-associated genes on these tumors. Although the results showed overlapping of genomic alterations between the two subtypes, trends including more frequent KRAS alterations in pancreatobiliary-type ampullary carcinoma (61 vs 29%) and more frequent mutations in APC in intestinal-type ampullary carcinoma (43 vs 17%) were observed. Of the entire cohort of 32 tumors, the most frequently mutated gene was TP53 (n=17); the most frequently amplified gene was ERBB2 (n=5); and the most frequently deleted gene was CDKN2A (n=6). In the second phase of the study, we aimed at validating our observation on ERBB2 and assessed ERBB2 amplification and protein overexpression in a series of 100 ampullary carcinomas. We found that (1) gene amplification and immunohistochemical overexpression of ERBB2 occurred in 13% of all ampullary carcinomas, therefore providing a potential target for anti-HER2 therapy in these tumors; (2) amplification and immunohistochemical expression correlated in all cases, thus indicating that immunohistochemistry could be used to screen tumors; and (3) none of the 14 ERBB2-amplified tumors harbored any downstream driver mutations in KRAS/NRAS, whereas 56% of the cases negative for ERBB2 amplification did, an observation clinically pertinent as downstream mutations may cause primary resistance to inhibition of EGFR family members.

Mixed adenoneuroendocrine carcinoma of the ampulla: two case reports.

Mixed adenoneuroendocrine carcinoma (MANEC) is a malignant tumor with adenocarcinoma and neuroendocrine components, with ≥30% of each component required. MANEC of the ampulla is rare. To the best of our knowledge, only 15 cases of MANEC of the ampulla have been reported in the English-language literature. Here, we report two cases of MANEC of the ampulla in two women aged 43 and 60 years, which was confirmed by histology after pancreaticoduodenectomy. These tumors contained neuroendocrine and adenocarcinoma components. The neuroendocrine components were positive for chromogranin A (CgA), synaptophysin (Syn) and CD56 by immunostaining. The adenocarcinoma components were negative for CgA, Syn and CD56. Both cases were T3N0M0 (Stage IIIA). They survived for 15 and 20 mo after surgery, respectively. A brief discussion about the histopathological features, clinical behavior and treatment of MANEC of ampulla, and review of the relevant literature are presented.

Type I Interferon Receptor Expression in Human Pancreatic and Periampullary Cancer Tissue.

OBJECTIVES: Interferons (IFNs) have several anticancer mechanisms. A number of clinical trials have been conducted regarding adjuvant IFN-α therapy in pancreatic cancer. Type I IFNs exert their effect via the type I IFN receptor (IFNAR-1, IFNAR-2c). The aims of the present study were to determine the type I IFN receptor expression in pancreatic and periampullary cancer tissues and to study its relation with clinicopathological factors. METHODS: Receptor expression was determined by immunohistochemistry in paraffin-embedded cancer tissue of 47 pancreatic and 54 periampullary cancer patients. RESULTS: The results demonstrated that 91.5% of the pancreatic tumors and 88.9% of the periampullary tumors showed expression of IFNAR-1, of which 23.4% and 13.0% were strongly positive, respectively. Regarding IFNAR-2c expression, 68.1% of the pancreatic tumors and 68.5% of the periampullary tumors were positive, of which 4.3% of the pancreatic tumors and none of the periampullary tumors had a strong expression. No statistically significant associations were found between type I IFN receptor expression and clinicopathological factors or survival. CONCLUSIONS: Type I IFN receptors are expressed in pancreatic and periampullary cancer tissues although with great intertumoral and intratumoral variability. A small proportion of both tumors showed a strong expression of the IFNAR-1; only a very small percentage of the pancreatic tumors showed strong expression of the IFNAR-2c.

The utility of immunohistochemistry in subtyping adenocarcinoma of the ampulla of vater.

Histologic classification of ampullary carcinomas into intestinal, pancreatobiliary, or other subtypes is easily achievable in some cases but difficult in others. Immunohistochemical (IHC) stains may allow distinction between the subtypes; however, their added value to routine hematoxylin and eosin (H&E) evaluation has not been systematically evaluated. Inconsistent histologic subtyping has hampered current clinical research and therapeutic trials. In this study, a consecutive series of 105 ampullary carcinomas was subtyped first by H&E evaluation and then by the evaluation of an IHC panel composed of CK7, CK20, CDX2, MUC1, and MUC2, and the added value of IHC was analyzed. By H&E, a consensus diagnosis, defined as concordant subtyping among at least 3 of the 4 independent study pathologists, was achieved in 81 of the 105 (77%) cases. There was excellent agreement for poorly differentiated and mucinous subtypes (κ=0.72 and 0.89, respectively) but only good agreement for intestinal and pancreatobiliary subtypes (κ=0.57 and 0.48, respectively) and poor agreement for mixed subtype (κ=0.09). By IHC, CK7 showed no informative value (being positive in ≥70% of the cases in both intestinal and pancreatobiliary subtypes), whereas a subtyping schema incorporating the combination staining patterns of CK20, CDX2, MUC1, and MUC2 did. By this schema, "intestinal subtype" was defined as having (1) positive staining for CK20 or CDX2 or MUC2 and negative staining for MUC1, or (2) positive staining for CK20, CDX2, and MUC2, irrespective of the MUC1 result; and "pancreatobiliary subtype" was defined as having positive staining for MUC1 and negative staining for CDX2 and MUC2, irrespective of CK20 results. Cases not fitting one of these 3 categories were regarded as "ambiguous" immunohistochemically. By combining this schema with H&E evaluation, 97 of the 105 cases (92%) could be classified into either intestinal or pancreatobiliary subtype. In particular, immunophenotyping allowed categorization of 75% of poorly differentiated adenocarcinomas and 69% of cases with mixed histologic features as either intestinal or pancreatobiliary subtype. Most mucinous adenocarcinomas (88%) were clearly intestinal subtype by IHC. Thus, our IHC schema enhanced the subtyping of ampullary carcinoma and, in combination with H&E evaluation, allowed a dichotomous classification in 92% of the cases. Should further independent studies reaffirm our findings, this schema may serve as a valuable tool in both diagnostic and research settings.

A case of ampullary gangliocytic paraganglioma.

Gangliocytic paragangliomas (GPs) are rare tumors of the duodenum, presenting as single sessile or pedunculated polypoid masses. Clinical manifestations of duodenal GPs can vary from an incidental finding at endoscopy to frequent upper gastrointestinal bleeding caused by mucosal ulceration and abdominal pain. GPs are considered benign, but the disease can recur and spread to regional lymph nodes. A 41-year-old female presented with abdominal pain. Upper gastrointestinal endoscopy revealed a subepithelial tumor of the ampulla of Vater in the second portion of the duodenum. The tumor was resected using the endoscopic mucosal resection technique. The tumor was diagnosed as benign GP of the duodenum using histological and immunohistochemical staining procedures.

Gastrointestinal stromal tumor of the ampulla of Vater: a case report.

Gastrointestinal stromal tumors (GISTs) usually develop in the stomach and small intestine and only rarely occur at the ampulla of Vater, with only 11 cases reported in the literature. We report a case of a GIST of the ampulla of Vater. A 36-year-old, previously healthy man presented with a loss of consciousness lasting a few minutes. A gastroduodenal endoscopy revealed a submucosal tumor with central ulceration at the ampulla of Vater. The enhanced computed tomography scan revealed a smooth-outlined hypervascular solid mass (24 mm × 30 mm) in the second part of the duodenum. Neither lymphadenopathy nor metastasis was observed. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed normal bile and pancreatic ducts. Biopsies were collected from the ulcerative lesion, and the tumor was diagnosed as a GIST. A submucosal tumor with central ulceration may be a characteristic form of GISTs of the ampulla of Vater, and biopsy studies are useful for the diagnosing such tumors. The patient underwent pancreatoduodenectomy, and the operative specimen revealed a 2.2-cm GIST with 1 mitosis per 50 high-power fields. The gold standard for treatment of GISTs is surgical resection without rupture of a capsule. If technically possible, local resection may be considered. However, when the location of the lesion presents challenges, a pancreatoduodenectomy should be performed for GIST of the ampulla of Vater.

MicroRNA profiling in periampullary carcinoma.

BACKGROUND: MicroRNA expression patterns in many physiological and oncogenic processes have been established. However, the role of aberrant miRNA expression in periampullary carcinoma (PAC) has not been elucidated. We hypothesize that PAC may have differential expression of miRNAs which may differentiate the tumor histological subtypes. METHODS: Fresh paired tumor and control samples were collected from the PAC patients undergoing Whipple's pancreaticoduodenectomy. Microarray miRNA profiling was performed utilizing tumor (n = 40) and control tissues; adjacent normal pancreas (n = 22), six each distal CBD, duodenum and ampulla. Data obtained was subjected to statistical and bioinformatic analysis. Differentially expressed miRNAs obtained were validated using qPCR in an independent set of samples. RESULTS: Comparison of PAC tissue samples with controls revealed 29 common and differentially expressed miRNAs (20 upregulated and 9 downregulated) with a higher statistical significance (p < 0.001) and fold change (log2 FC > 1.5). A subset of 16 miRNAs (15 overexpressed and 1 underexpressed) differed in expression levels between pancreatobiliary and intestinal subtypes. Among these, miR-375, miR-31 and miR-196a expressions varied significantly between histological subtypes. Differential expression profiles of miRNAs specific to TNM staging was also observed in PAC subtypes. Target gene prediction for the differentially expressed miRNAs in PAC revealed that target genes are enriched for certain pathways. Particularly, Wnt signaling pathway genes appear to be relevant targets for most of the differentially expressed miRNAs. CONCLUSION: Differentially expressed common miRNA signatures identified in PAC subgroups may have a role in pathogenesis of PAC and miR-375, miR-31 and miR-196a expression patterns may differentiate PAC subtypes.

Recurrent acute pancreatitis in a patient with wirsungocele and neuroendocrine tumor of ampulla of Vater.

CONTEXT: Wirsungocele has recently been shown to be associated with acute recurrent, severe necrotizing pancreatitis and chronic pancreatitis or chronic pain in abdomen. Till to date there is no report on association of wirsungocele with an ampullary neuroendocrine tumor, and recurrent pancreatitis. CASE REPORT: We report a first ever case of wirsungocele diagnosed on EUS, its association with neuroendocrine tumor of ampulla and recurrent acute pancreatitis. CONCLUSION: This case report highlights the diagnostic utility of EUS in diagnosing small ampullary pathology like wirsungocele and neuroendocrine tumor.

Cytokeratin 20 (CK20) and apomucin 1 (MUC1) expression in ampullary carcinoma: Correlation with tumor progression and prognosis.

BACKGROUND: We assessed the expression of cytokeratin (CK) and apomucin (MUC) in ampullary carcinoma (AC) to develop a system for the classification of ACs on the basis of their clinical significance. METHOD: We studied the expressions of CK7, CK20, MUC1, MUC2, MUC5AC, and MUC6 in 43 patients with ACs. Clinical data were obtained retrospectively by examining surgically resected ACs of the patients. RESULTS: We classified the cases into 3 groups: tumors expressing CK20 and lacking MUC1 (intestinal type [I-type], 26%), tumors expressing MUC1 and lacking CK20 (pancreatobiliary type [PB-type], 35%), and those expressing or lacking both CK20 and MUC1 (other type [O-type], 39%). Eight (73%) of 11 I-type carcinomas, 3 (20%) of 15 PB-type carcinomas, and 4 (24%) of 17 O-type carcinomas were classified as pT1. The number of I-type carcinomas in the early tumor stages was significantly higher than the number of PB- and O-type carcinomas (p = 0.014 and p = 0.018, respectively). The 5-year survival rates for pT1, pT2, and pT3 tumors were 76%, 33%, and 22%, respectively (p < 0.001). Rates of MUC5AC and MUC6 coexpression for I-type, PB-type, and O-type tumors were 18%, 13%, and 53%, respectively. There was a significant correlation between MUC5AC and MUC6 coexpression and O-type characteristics (p = 0.031). The five-year survival rates for O-type ACs with and without MUC5AC and MUC6 coexpression were 71% and 17%, respectively (p = 0.048). CONCLUSIONS: The immunohistochemical subtypes based on CK and MUC expression correlated with tumor progression. Gastric MUC5AC and MUC6 coexpression correlated with better prognosis for O-type ACs.

A case of gangliocytic paraganglioma in the ampulla of Vater.

BACKGROUND: Duodenal gangliocytic paraganglioma is an extremely rare tumor and few cases have been reported to date. CASE PRESENTATION: The authors report a case of gangliocytic paraganglioma verified by post-op pathology after pancreaticoduodenectomy for a tumor in the ampulla of Vater. The 56-year-old male patient concerned visited our emergency room with melena that started one week prior to hospitalization. The patient was diagnosed to have a tumor in the ampulla of Vater with bleeding on its surface. However post-op, he was diagnosed as having gangliocytic paraganglioma by immunohistochemistry. CONCLUSION: This tumor has precise clinical implications, and if continuous follow up is conducted after careful diagnosis and surgical treatment, invasive major operations, such as, radical pancreaticoduodenectomy can be avoided.

Histopathologic features and microsatellite instability of cancers of the papilla of vater and their precursor lesions.

The prevalence and development of microsatellite instability (MSI) and underlying mismatch repair (MMR) deficiency in the carcinogenesis of adenocarcinomas of the papilla of Vater and their precursor lesions are not well established. We analyzed 120 ampullary adenomas (31 pure adenomas and 89 carcinoma-associated adenomas) and 170 pure adenocarcinomas for MSI, immunohistochemical expression of MMR proteins and specific histopathologic features. The most common histologic subtype was intestinal (46.5%), followed by pancreatobiliary (23.5%), poorly differentiated adenocarcinomas (12.9%), intestinal-mucinous (8.2%), and invasive papillary carcinomas (5.3%). Eight of 89 adenomas (9%) and 15/144 carcinomas (10%) showed high microsatellite instability (MSI-H), 10/89 adenomas (11%) and 5/144 carcinomas (4%) showed low microsatellite instability (MSI-L), and 71/89 adenomas (80%) and 124/144 carcinomas (86%) were microsatellite stable (MSS). MSI analysis from carcinomas contiguous with an adenomatous component (n=54) exhibited concordant results in 6/8 (75%) MSI-H and 42/46 (91.3%) MSS tumors. Of 14 carcinomas with MSI-H, 7 showed loss of MLH1 and 5/6 (83%) MLH1 promoter methylation, and 2 carcinomas showed simultaneous loss of MSH2 and MSH6. Two carcinomas and 3 adenomas with MSI-H revealed exclusive loss of MSH6. MSI-H cancers were significantly associated with intestinal mucinous subtype (P<0.001), high tumor grade (P=0.003), expansive growth pattern (P=0.044), and marked lymphoid host response (P=0.004). Patients with MSI-H carcinoma had a significantly longer overall survival (P=0.0082) than those with MSI-L or MSS tumors. Our findings indicate that the MSI-phenotype is an early event, which develops at the stage of adenoma and is reliably detectable in the precursor lesion. The MMR deficient molecular pathway of carcinogenesis is associated with a histopathologic phenotype in ampullary cancer, similar to the one that has been well described in colon cancer.