Enteroblastic adenocarcinoma of the ampulla of Vater.

Adenocarcinoma with enteroblastic differentiation is a rare histologic subtype of adenocarcinoma of the gastrointestinal tract that shows unique histologic and immunohistochemical features that resemble fetal intestinal epithelium. This histological subtype has been widely described in the stomach, where it most frequently appears, but, in other locations, it is misdiagnosed because of the poor experience in routine diagnostic setting. Here we present a case of an 87-year-old male with an adenocarcinoma of the ampulla of Vater with enteroblastic differentiation with a literature review of the cases described of this subtype in this location to date. The anatomical peculiarity of the ampulla, joined with the infrequent nature of this histological subtype, makes this case of great interest to aid to better characterize the biological behavior of these tumors.

STIM1/SOX2 proteins are co-expressed in the tumor and microenvironmental stromal cells of pancreatic ductal adenocarcinoma and ampullary carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) and ampullary carcinoma (AAC) are lethal malignancies with modest benefits from surgery. SOX2 and STIM1 have been linked to anticancer activity in several human malignancies. This study included 94 tumor cases: 48 primary PDAC, 25 metastatic PDAC, and 21 primary AAC with corresponding non-tumor tissue. All cases were immunohistochemically stained for STIM1 and SOX2 and results were correlated with clinicopathologic data, patient survival, and BCL2 immunostaining results. Results revealed that STIM1 and SOX2 epithelial/stromal expressions were significantly higher in PDAC and AAC in comparison to the control groups. STIM1 and SOX2 expressions were positively correlated in the primary and metastatic PDAC (P = 0.016 and, P = 0.001, respectively). However, their expressions were not significantly associated with BCL2 expression. SOX2 epithelial/stromal expressions were positively correlated with the large tumor size in the primary AAC group (P = 0.052, P = 0.044, respectively). STIM1 stromal and SOX2 epithelial over-expressions had a bad prognostic impact on the overall survival of AAC (P = 0.002 and P = 0.001, respectively). Therefore, STIM1 and SOX2 co-expression in tumor cells and intra-tumoral stroma could contribute to the development of PDAC and AAC. STIM1/SOX2 expression is linked to a bad prognosis in AAC.

New gel immersion endoscopic ultrasonography technique for accurate periampullary evaluation.

BACKGROUND: Visualization of the pancreatobiliary junction is one of the challenges faced by endoscopic ultrasonography (EUS). The water-filling technique, which allows for the observation of the ampulla at a suitable distance by injecting water into the lumen of the duodenum, was used for this purpose. However, a new gel immersion technique has recently been introduced for visualizing the gastrointestinal tract. This study investigated the effectiveness of visualizing the pancreatobiliary junction in EUS by comparing both water filling and the new gel immersion technique in identical cases. METHODS: The study ran from June to December 2021. Ten images from each technique were retrospectively compared by three independent researchers. The primary result of the study was the number of images depicting the "Pancreatic and Biliary Ducts Penetrating the Duodenal Muscularis Propria" (defined as Excellent observation) in each technique. The secondary outcome was defined as gel immersion technique's safety and impact on duodenal lumen distension. RESULTS: Ten patients used the gel immersion technique. All patients underwent the water-filling technique first, followed by gel injection after the water was completely aspirated. The average number of pictures rated as "Excellent observation," which is the primary outcome, was significantly higher with the gel immersion technique than with water filling, and no adverse events were observed. The subanalysis revealed that both convex and radial echoendoscopes are equally effective at depicting the ampulla with the gel immersion technique. CONCLUSIONS: The ability to depict the pancreatobiliary junction using the gel immersion technique is superior to that of the water-filling method, which may allow for a more detailed assessment of the ampullary region with both radial and convex echoendoscopes. This can be a useful EUS technique for diagnosing pancreaticobiliary maljunction or periampullary tumors.

Prognostic value of nodal staging classification and number of examined lymph nodes among patients with ampullary cancer.

BACKGROUND: Metastatic disease in the regional lymph nodes (LNs) is a strong indicator of worse outcomes among patients after curative-intent resection of ampullary cancer (AC). This study aimed to ascertain the threshold number of examined LNs (ELNs) for AC to compare the prognosis accuracy of various nodal classification schemes relative to long-term prognosis. METHODS: Patients who underwent pancreatoduodenectomy (PD) for AC (2004-2019) were identified using the National Cancer Database. Locally weighted regression scatter plot smoothing (LOWESS) curves were used to ascertain the optimal cut point for ELNs. The accuracy of the American Joint Committee on Cancer N classification, LN ratio, and log odds transformation (LODDS) ratio to stratify patients relative to survival was examined. RESULTS: Among 8127 patients with AC, 67% were male with a median age of 67 years (IQR, 59-74). Tumors were most frequently classified as T3 (34.9%), followed by T2 (30.6%); T1 (12.9%) and T4 (17.6%) were less common. LN metastasis was identified in 4606 patients (56.7%). Among patients with nodal disease, 37.0% and 19.7% had N1 and N2 disease, respectively. The LOWESS curves identified an inflection cutoff point in the hazard of survival at 20 ELNs. The survival benefit of 20 ELNs was more pronounced among patients without LN metastasis vs patients with N1 disease (median overall survival [OS]: 54.1 months [IQR, 45.9-62.1] in ≥20 ELNs vs 39.0 months [IQR, 35.8-42.2] in <20 ELNs; P < .001) or N2 disease (median OS: 22.5 months [IQR, 18.9-26.2] in ≥20 ELNs vs 25.4 months [IQR, 23.3-27.6] in <20 ELNs; P < .001). When comparing the 4 different N classification schemes, the LODDS classification scheme yielded the highest predictive ability. CONCLUSIONS: Evaluation of a minimum of 20 LNs was needed to stratify patients with AC relative to the prognosis and to minimize stage migration. The LODDS nodal classification scheme had the highest prognostic accuracy to differentiate survival among patients after PD for AC.

Underwater endoscopic papillectomy for a small neuroendocrine tumor of the ampulla of Vater.

Neuroendocrine tumors (NETs) of the ampulla of Vater are rare. Therefore, there is a lack of comprehensive information regarding their pathogenesis. We herein present the case of a patient with a 5-mm ampullary NET who demonstrated the presence of lymphatic invasion after undergoing endoscopic papillectomy. A 44-year-old woman was referred to our hospital for treatment of a grade 1 NET in the ampulla of Vater. Endoscopic ultrasonography revealed a hypoechoic mass within the submucosal layer without obvious infiltration into the common bile duct or the main pancreatic duct. We performed underwater endoscopic papillectomy (UEP) to remove the tumor with a negative margin. Pathological evaluation of the resected specimen showed a grade 1 NET with a negative margin. However, pancreaticoduodenectomy was subsequently performed because of the risk of lymph node metastasis, which was expected due to the significant number of NET cells infiltrating the endothelium of the lymphatic vessels. No lymph node metastasis or recurrence was observed during the 26-month follow-up period. UEP is a useful method to achieve complete resection for diagnostic and therapeutic purposes. UEP may be a novel option for endoscopic treatment of ampullary NET.

Clinical impact of ampulla of Vater cancer subtype classification based on immunohistochemical staining.

BACKGROUND: The histological subtype is an important prognostic factor for ampulla of Vater (AoV) cancer. This study proposes a classification system for the histological subtyping of AoV cancer based on immunohistochemical (IHC) staining and its prognostic significance. METHODS: Seventy-five AoV cancers were analyzed for cytokeratin 7 (CK7), CK20, and causal-type homeobox transcription factor 2 (CDX2) expression by IHC staining. We differentiated the subtypes (INT, intestinal; PB, pancreatobiliary; MIX, mixed; NOS, not otherwise specified) into classification I: CK7/CK20, classification II: CK7/CK20 or CDX2, classification III: CK7/CDX2 and examined their associations with clinicopathological factors. RESULTS: Classifications I, II, and III subtypes were INT (7, 10, and 10 cases), PB (43, 37, and 38 cases), MIX (13, 19, and 18 cases), and NOS (12, 9, and 9 cases). Significant differences in disease-free survival among the subtypes were observed in classifications II and III using CDX2; the PB and NOS subtype exhibited shorter survival time compared with INT subtype. In classification III, an association was revealed between advanced T/N stage, poor differentiation, lymphovascular invasion (LVI), the PB and NOS subtypes, and recurrence risk. In classification III, the subtypes differed significantly in T/N stage and LVI. Patients with the PB subtype had advanced T and N stages and a higher incidence of LVI. CONCLUSIONS: Classification using CDX2 revealed subtypes with distinct prognostic significance. Combining CK7 and CDX2 or adding CDX2 to CK7/CK20 is useful for distinguishing subtypes, predicting disease outcomes, and impacting the clinical management of patients with AoV cancer.

Revolutionizing anti-HER2 therapies for extrahepatic cholangiocarcinoma and gallbladder cancer: Current advancements and future perspectives.

Biliary tract cancers (BTCs) encompass a heterogeneous group of rare tumors, including intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), gallbladder cancer (GBC) and ampullary cancer (AC). The present first-line palliative treatment regimen comprises gemcitabine and cisplatin in combination with immunotherapy based on two randomized controlled studies. Despite the thorough investigation of these palliative treatments, long-term survival remains low. Moving beyond conventional chemotherapies and immunotherapies, the realm of precision medicine has demonstrated remarkable efficacy in malignancies such as breast and gastric cancers, characterized by notable HER2 overexpression rates. In the context of biliary tract cancer, significant HER2 alterations are observed, particularly within eCCA and GBC, heightening the interest in precision medicine. Various anti-HER2 therapies, including trastuzumab, pertuzumab, trastuzumab-deruxtecan, zanidatamab and neratinib, have undergone investigation. The objective of this review is to summarize the current evidence and outline future directions of targeted HER2 treatment therapy in patients with biliary tract tumors, specially extrahepatic cholangiocarcinoma and gallbladder cancer.

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.

Hybrid resection versus conventional resection for laterally spreading lesions of the papilla.

BACKGROUND AND AIMS: Although conventional hot snare resection (CR) of laterally spreading lesions of the major papilla (LSL-Ps) is effective, it can be associated with delayed bleeding in upward of 25% of cases. Given the excellent safety profile of cold snare polypectomy in the colorectum, we investigated the efficacy and safety of a novel hybrid resection (HR) technique for LSL-P management, consisting of hot snare papillectomy plus cold snare resection of the laterally spreading component. METHODS: A prospective cohort of patients underwent HR in a tertiary referral center over 60 months until December 2022. This cohort was compared with a historical cohort of patients who underwent CR at the same institution over 120 months until August 2017. The primary outcomes were recurrence and bleeding. RESULTS: Twenty patients underwent HR (14 female; mean age 65.2 ± 12.2 years). Median lesion size was 30 mm (interquartile range, 25.0-47.5 mm). Recurrent or residual adenoma (RRA) was greater with HR (58.8% [n = 10] vs 29.8% [n = 14]; P = .034). The odds ratio for recurrence was 3.6 times (95% CI, 1.2-11.0) higher with HR (P = .027). RRA was multifocal in 4 (40%) and had a composite RRA volume >10 mm in 7 (70%). The median number of procedures required to treat RRA was higher with HR (4 vs 1, P = .002). There was no difference between CR and HR for intraprocedural bleeding (41.1% [n = 23] vs 25% [n = 5]; P = .587) or delayed bleeding (25.0% vs 10.0%, P = .211). There were no perforations. CONCLUSIONS: The novel HR technique for LSL-P management is associated with a high rate of RRA that is recalcitrant to treatment, without mitigating the risk of intraprocedural or delayed bleeding. Therefore, CR should remain the mainstay management option for treating patients with an LSL-P. (Clinical trial registration number: NCT02306603.).

The timing of recurrence after endoscopic papillectomy.

BACKGROUND: Endoscopic papillectomy (EP) offers a safe and effective method for resection of ampullary adenomas. Data regarding the long-term resolution of adenoma following EP are limited. The aim of this study therefore was to examine the timing of recurrence after EP of ampullary adenomas. METHODS: This was a single-center retrospective study including patients who received EP for ampullary adenomas from 8/2000 to 1/2018. Patients with confirmed complete eradication of adenoma were included in the recurrence analysis with recurrence defined as finding adenomatous histology after 1 negative surveillance endoscopy. Kaplan-Meier estimates were calculated to determine recurrence rates. RESULTS: Of the 165 patients who underwent EP, 136 patients (mean age 61.9, 51.5% female) had adenomatous histology with a mean lesion size of 21.2 mm. A total of 124 (91.2%) achieved complete eradication with a follow-up of 345.8 person-years. Recurrence occurred in 20 (16.1%) patients at a mean of 3.2 (± 3) years (range 0.5-9.75 years) for a recurrence rate of 5.8 (95% CI 3.6-8.8) per 100 person-years. Nine (45%) recurrences occurred after the 1st 2 years of surveillance. Recurrence rate did not differ by baseline pathology [low-grade dysplasia: 5.2 (95% CI 3.0-9.0), high-grade dysplasia: 6.9 (95% CI 2.3-15.5), adenocarcinoma: 7.7 (95% CI 0.9-25.1)]. CONCLUSION: Recurrence remains a significant concern after EP. Given the timing of recurrence, long surveillance periods may be necessary. Larger multicenter studies are needed, however, to determine appropriate surveillance intervals.

Histologic characterization of the major duodenal papilla and association with concurrent biliary, pancreatic, and intestinal pathology in cats.

Conjoining of the major pancreatic duct and common bile duct at the major duodenal papilla (MDP) is suspected to predispose cats to the clinical syndrome of "triaditis." However, microanatomy of the MDP or presence of lesions at the MDP has not been assessed in cats with or without triaditis. The aims of this study were to characterize feline MDP histomorphology and to identify associations between MDP anatomy/disease and the presence of biliary, pancreatic, or intestinal inflammation or neoplasia. Histologic assessment was prospectively performed on the MDP, duodenum, jejunum, ileum, liver, and pancreas from 124 client-owned cats undergoing postmortem examination. The majority of cats (104/124, 84%) had a complex ductular network at the MDP, with no distinction between pancreatic and common bile ducts. Lymphoid aggregates at the MDP were common (63/124, 51%). Inflammation of the MDP (MDPitis) was present in 35 of 124 cats (28%) and was often concurrent with cholangitis, pancreatitis, or enteritis (32/35, 91%), but was only associated with enteritis (19/35, 54%, P < .05). Triaditis was less common (19/124, 15%), but was associated with both conjoined MDP anatomy (19/19, 100%, P < .05) and MDPitis (12/19, 63%, P < .05). Neoplasia was present in 37 of 124 cats (29%), with lymphoma (28/37, 78%) predominating. Enteropathy-associated T-cell lymphoma type 2 (EATL2) was most common (n = 16/37, 43%) and was associated with triaditis and MDPitis (P < .05). These findings suggest that anatomy, immune activation, and/or inflammation of the MDP may play a role in the pathogenesis of triaditis. Further studies are needed to elucidate the relationships between triaditis, MDPitis, and EATL2.

Outcomes of endoscopic papillectomy of ampullary carcinoma and factors affecting additional surgery.

BACKGROUND/PURPOSE: Data on the prognosis of endoscopic papillectomy (EP) for ampullary carcinoma (AC) is limited; therefore, we aimed to identify the factors associated with endoscopically controlled AC. METHODS: Between January 2003 and October 2022, 75 patients underwent EP for ampullary tumors and were diagnosed with AC based on the pathological features of the resected tissue. The factors associated with additional surgery after EP were also evaluated. RESULTS: A total of 67 patients had ACs ranging from carcinoma in situ to tumors limited to the mucosa (M group), and eight patients had ACs ranging from those limited to the sphincter of Oddi to those invading the duodenal muscularis propria (OD group). The 3-year endoscopic tumor control (condition not requiring additional surgery) rates in the M and OD groups were 90.8% and 84.6% (p = .033), respectively. In the M group, the presence of tumor components in the resection margins was the only significant factor associated with additional surgeries (p = .010) in the univariate analysis. The 3-year endoscopic tumor control rates were 100% for negative and uncertain resection margins and 76.6% for positive margins (p = .009). CONCLUSIONS: If the AC is confined to the mucosa and the resection margins are negative or uncertain, the tumor can be well-controlled endoscopically.

Impact of extra-ampullary duodenal adenocarcinoma subtypes on surgical and oncological outcomes following pancreaticoduodenectomy.

BACKGROUND: There is little information about the relevance of extra-ampullary duodenal adenocarcinoma (EDA) subtypes. The aim of this study was to evaluate the impact of EDA subtypes on surgical and oncological outcomes following pancreatoduodenectomy (PD). METHODS: Consecutive patients undergoing PD for EDA from 2000 to 2019 were analyzed. Results were stratified by pathologic subtype (intestinal versus non-intestinal). Uni-and multivariable analyses were performed using standard statistical methods. RESULTS: The study population consisted of 70 patients, of whom 49 (70%) had an intestinal phenotype. EDA with intestinal phenotype was more frequently proximal to the Ampulla of Vater, while non-intestinal EDA was more frequently found distally (76% vs. 33%, p = 0.002). Patients with intestinal EDA were less likely to experience severe morbidity, with decreased reoperation and unplanned Intensive Care Unit admission rates relative to non-intestinal subtypes (2% vs. 29% p = 0.002, and 2% vs. 19%, p = 0.007, respectively). The median follow-up post-pancreatectomy was 73 months. Intestinal EDA was associated with improved overall and disease-free survival, with 3-year and 5-year survival rates of 71% vs. 29% and 53% vs. 24%, respectively. (p = 0.019 and p = 0.025). CONCLUSION: Intestinal-type EDA, which more often arises from supra-ampullary duodenum, was associated with better postoperative outcomes and improved survival.

Differentiation of malignant from benign ampullary strictures: A prediction nomogram based on MR imaging and clinical findings.

PURPOSE: To construct a predictive nomogram based on contrast-enhanced magnetic resonance imaging (MRI) and clinical findings for differentiating malignant from benign ampullary strictures. METHOD: In this retrospective study, 76 patients with ampullary strictures (51 benign and 25 malignant) who underwent contrast-enhanced MRI were enrolled. Imaging findings were evaluated independently by two abdominal radiologists who reached consensus. Clinical findings were also collected. Significant findings for malignant ampullary strictures were assessed by univariable and multivariable logistic regression analyses. Based on the results of multivariable analysis, a nomogram to differentiate malignant from benign ampullary strictures was developed and internally validated. RESULTS: In multivariable analysis, presence of an ampullary mass (odds ratio [OR]: 8.42, p = 0.047), bulging ampulla (OR: 8.32, p = 0.033), diffusion restriction of the ampulla (OR: 42.76, p = 0.004) on MRI, and jaundice (OR: 12.41, p = 0.019) were significant predictors of malignant ampullary strictures. A predictive nomogram was constructed using these findings. Among them, diffusion restriction of the ampulla showed the highest OR and predictor score on the nomogram. The calibration plots for internal validation achieved strong agreement between the predicted probabilities and the actual rates of malignant ampullary strictures. CONCLUSION: A combination of significant contrast-enhanced MRI and clinical findings of ampullary mass, bulging ampulla, diffusion restriction of the ampulla, and jaundice may be useful in the prediction of malignant ampullary stricture.

Clinical features and distribution of the APC variant in duodenal and ampullary polyps in patients with familial adenomatous polyposis: a multicenter retrospective cohort study in Japan.

BACKGROUND: Management of duodenal or ampullary adenomas in patients with familial adenomatous polyposis (FAP) is a major challenge for clinicians. Insufficient data are available to evaluate the clinical manifestations and distribution of adenomatous polyposis coli (APC) variants in these patients. METHODS: We enrolled 451 patients with data regarding duodenal or ampullary polyps from 632 patients with FAP retrospectively registered in a nationwide Japanese multicenter study. Clinicopathological features and distribution of APC variants were compared between patients with and without duodenal or ampullary polyps. RESULTS: Duodenal and ampullary polyps were found in 59% and 18% of patients with FAP, respectively. The incidence of duodenal cancer was 4.7% in patients with duodenal polyps, and that of ampullary cancer was 18% in patients with ampullary polyps. Duodenal polyps were significantly associated with the presence of ampullary polyps and jejunal/ileal polyps. Duodenal polyps progressed in 35% of patients with a median follow-up of 776 days, mostly in those with early Spigelman stage lesions. Ampullary polyps progressed in 50% of patients with a follow-up of 1484 days. However, only one patient developed a malignancy. The proportion of patients with duodenal polyps was significantly higher among those with intermediate- or profuse-type APC variants than attenuated-type APC variants. The presence of duodenal polyps was significantly associated with ampullary and jejunal/ileal polyps in patients with intermediate- or profuse-type APC variants. CONCLUSIONS: Periodic endoscopic surveillance of the papilla of Vater and small intestine should be planned for patients with FAP with duodenal polyps.

[Case of Mixed Neuroendocrine-Non-Neuroendocrine Neoplasm of the Papilla of Vater Metastasizing to the Lung after Resection].

A 79-year-old man visited a hospital for right upper abdominal pain and nausea. After conservative treatment for cholangitis and pancreatitis owing to a pancreatic head lesion, he was referred to our hospital for further evaluation and treatment of the lesion. He was diagnosed with pancreatic head cancer or carcinoma of papilla of Vater and underwent subtotal stomach- preserving pancreaticoduodenectomy. Postoperative histopathological examination revealed the coexistence of adenocarcinoma( 60%)and neuroendocrine carcinoma(40%)components, consistent with the diagnosis of mixed neuroendocrine- non-neuroendocrine neoplasm(MiNEN). In addition, regional lymph node metastasis of the adenocarcinoma component was found. Adjuvant chemotherapy was not administered because of a poor performance status. Lung metastasis occurred 13 months after surgery. Chemotherapy with S-1 was administered, and partial response was obtained 17 months after surgery. Herein, we report this rare case of MiNEN of the papilla of Vater with lung metastasis.

Endoscopic papillectomy combined with endoscopic retrograde cholangio-pancreatography for duodenal gangliocytic paraganglioma: A case report.

RATIONALE: Gangliocytic paraganglioma is a rare tumor that can occur in several organs throughout the body. Gangliocytic paraganglioma of the main duodenal papilla is even rarer. This study analyzes and discusses the endoscopic management of a case of gangliocytic paraganglioma of the main duodenal papilla and reviews the relevant literature. It is hoped that this study will increase clinicians' awareness of this disease. PATIENT CONCERNS: Electron endoscopy reveals a duodenal main papillary tumor, and the patient desires further clarification of the nature of the tumor and the next step in the treatment plan. DIAGNOSES: Duodenal gangliocytic paraganglioma. INTERVENTIONS: As the patient lesion was located in the main duodenal papilla, we successfully performed endoscopic minimally invasive treatment of the tumor by endoscopic papillectomy combined with endoscopic retrograde cholangiopancreatography. OUTCOMES: The patient was discharged after the postoperative removal of the nasobiliary drain and returned to the hospital 2 months later to have the biliary stent removed; the patient was in good general condition at follow-up. LESSONS: For duodenal main papillary tumor, we need to be alert to the possibility of gangliocytic paraganglioma. Since the tumor is located in the submucosa of the juxta-abdominal region, the preoperative biopsy positivity rate is low, and the tumor is often adjacent to or involves the biliopancreatic duct, endoscopic resection combined with endoscopic retrograde cholangiopancreatography can be considered for diagnosis and treatment.

Current status of and future issues related to endoscopic papillectomy.

Endoscopic papillectomy is widely performed to treat duodenal papillary tumors, particularly at high-volume centers. It is indicated for adenomas without intraductal extension of the bile or pancreatic ducts. However, despite numerous reports of carcinomas that expand the indications to include well-differentiated adenocarcinomas that do not invade the sphincter of Oddi, the low agreement between biopsy and final pathological diagnosis, as well as the current inability of imaging modalities to diagnose sphincter of Oddi invasion, makes it difficult to consider expanding indications. Although complications can be prevented by certain methods, such as pancreatic duct stenting, and the frequency of severe complications has decreased, the safety of the procedure remains unconfirmed. In the future, this technology is expected to progress and enable wider applications, including those in tumors with extensive horizontal spread and those with intraductal extension of the bile and pancreatic ducts. Such technology may also improve the safety and accuracy of diagnosis.