Can the location of the mural nodule indicate benign or malignant in branch duct-type intraductal papillary mucinous neoplasm of the pancreas?

BACKGROUND/OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are classified into main duct (MD)-type IPMNs, branch duct (BD)-type IPMNs, and mixed type IPMNs. While MD-type IPMN has a high risk of malignancy and should therefore be considered for resection if the patient is fit, BD-type IPMN needs to be carefully judged for surgical indication. The decision to resect BD-type IPMN is often based on international consensus Fukuoka guidelines 2017, but further investigation is required. In this study, we focused on whether the location of the mural nodule (MN) could be an indicator of malignancy.

METHODS

We enrolled 17 cases who had been diagnosed BD-type IPMNs which were surgically resected from January 2016 to December 2019. These cases were classified into benign and malignant group. Subsequently, a clinicopathological study was conducted based on the localization of MN (MN-central type or MN-peripheral type).

RESULTS

Although MN was found in 57% (4/11) in the benign group, 88% (7/8) was noted in the malignant group, indicating the presence of MN to be more common in the malignant group. Those with MN consisted of 6 cases of MN-central type and 5 cases of MN-peripheral type. All cases of central type were malignant compared to only one case of the peripheral group being confirmed on histology as cancer.

CONCLUSION

BD-IPMN with central mural nodule should be considered high risk for malignancy.

Guidance for diagnosing autoimmune pancreatitis with biopsy tissues

The biopsy-based diagnosis of autoimmune pancreatitis (AIP) is difficult but is becoming imperative for pathologists due to the increased amount of endoscopic ultrasound-guided biopsy tissue. To cope with this challenge, we propose guidance for the biopsy diagnosis of type 1 AIP. This guidance is for pathologists and comprises three main parts. The first part includes basic issues on tissue acquisition, staining, and final diagnosis, and is intended for gastroenterologists as well. The second part is a practical guide for diagnosing type 1 AIP based on the AIP clinical diagnostic criteria 2018. Inconsistent histological findings, tips for evaluating IgG4 immunostaining and key histological features including the ductal lesion and others are explained. Storiform fibrosis and obliterative phlebitis are diagnostic hallmarks but are sometimes equivocal. Storiform fibrosis is defined as spindle-shaped cells, inflammatory cells and fine collagen fibers forming a flowing arrangement. Obliterative phlebitis is defined as fibrous venous obliteration with inflammatory cells. Examples of each are provided. The third part describes the differentiation of AIP from pancreatic ductal adenocarcinoma (PDAC), focusing on histological features of acinar-ductal metaplasia in AIP, which is an important mimicker of PDAC. This guidance will help standardize pathology reports of pancreatic biopsies for diagnosing type 1 AIP.

A case of pancreatic mixed acinar-neuroendocrine carcinoma successfully diagnosed with endoscopic ultrasound-guided fine needle aspiration

Mixed acinar-neuroendocrine carcinoma (MAEC) of the pancreas is a rare entity, and obtaining a preoperative diagnosis is difficult. We report a case of pancreatic MAEC successfully diagnosed with EUS-FNA. The case was a 72-year-old male with upper abdominal pain. Abdominal CT showed an irregular, hypovascular tumor of pancreatic tail. EUS-FNA was performed using a 22G needle. Immunostaining revealed positive results for the acinar marker trypsin and the neuroendocrine markers chromogranin A and synaptophysin. The possibility for MAEC was considered. He underwent distal pancreatectomy and splenectomy. Immunohistochemical examination of the tumor cells showed a wide range of positivity for bcl-10 and trypsin as well as for chromogranin A and synaptophysin, but negative results for CA19-9 and AFP. Considering that ≥ 30% tumors were positive for both acinar and neuroendocrine markers, the patient was diagnosed with MAEC.

High expression levels of polymeric immunoglobulin receptor are correlated with chemoresistance and poor prognosis in pancreatic cancer

Pancreatic cancer has extremely poor prognosis, warranting the discovery of novel therapeutic and prognostic markers. The expression of polymeric immunoglobulin receptor (pIgR), a key component of the mucosal immune system, is increased in several cancers. However, its clinical relevance in pancreatic cancer remains unclear. In the present study, the prognostic value of pIgR in pancreatic cancer patients after surgical resection was assessed and it was determined that the expression of pIgR was correlated with poor prognosis. Ten pancreatic cancer patient‑derived xenograft (PDX) lines were established, followed by next‑generation sequencing of tumor tissues from these lines after standard chemotherapy. Immunohistochemical analysis of chemoresistance‑related molecules using 77 pancreatic cancer tissues was also performed. The expression of pIgR mRNA in the PDX group treated with anticancer drugs was higher than in the untreated group. High pIgR expression in tissue specimens from 77 pancreatic cancer patients was significantly associated with poor prognosis and was revealed to be an independent prognostic factor, predicting poor outcomes. High pIgR mRNA and protein levels were independent prognostic factors, indicating that pIgR could be a novel predictor for poor prognosis of pancreatic cancer patients.

A case of primary pancreatic schwannoma diagnosed by endoscopic ultrasound-fine needle aspiration

Pancreatic schwannoma is difficult to diagnose preoperatively. A 79-year-old man was found to have a 9-mm pancreatic mass on abdominal ultrasonography. On EUS, there was a 9-mm, clearly demarcated, round, solid, hypo-echoic mass in the pancreatic body. The differential diagnosis included a pancreatic neuroendocrine tumor, a solid-pseudopapillary neoplasm, and an atypical pancreatic cancer. EUS-FNA was performed with a 22G needle. On pathology examination, spindle-shaped tumor cells were seen proliferating in bundles. On immunostaining, the lesion was negative for c-kit, CD34, and α-SMA but positive for S-100 protein. The MIB-1 index was < 2%. Based on the above findings, the lesion was diagnosed as a benign pancreatic schwannoma. We, therefore, decided to follow the patient with careful observation rather than resecting the lesion surgically. The tumor has not changed significantly after 3 years of follow-up. EUS-FNA is useful for the diagnosis of pancreatic schwannoma. If the tumor can be determined to be benign preoperatively, unnecessary surgery can be avoided. EUS-FNA should be actively implemented for pancreatic tumors that are difficult to diagnose definitively on imaging.

High expression of olfactomedin-4 is correlated with chemoresistance and poor prognosis in pancreatic cancer

Pancreatic cancer has an extremely poor prognosis, and identification of novel predictors of therapeutic efficacy and prognosis is urgently needed. Chemoresistance-related molecules are correlated with poor prognosis and may be effective targets for cancer treatment. Here, we aimed to identify novel molecules correlated with chemoresistance and poor prognosis in pancreatic cancer. We established 10 patient-derived xenograft (PDX) lines from patients with pancreatic cancer and performed next-generation sequencing (NGS) of tumor tissues from PDXs after treatment with standard drugs. We established a gene-transferred tumor cell line to express chemoresistance-related molecules and analyzed the chemoresistance of the established cell line against standard drugs. Finally, we performed immunohistochemical (IHC) analysis of chemoresistance-related molecules using 80 pancreatic cancer tissues. From NGS analysis, we identified olfactomedin-4 (OLFM4) as having high expression in the PDX group treated with anticancer drugs. In IHC analysis, OLFM4 expression was also high in PDXs administered anticancer drugs compared with that in untreated PDXs. Chemoresistance was observed by in vitro analysis of tumor cell lines with forced expression of OLFM4. In an assessment of tissue specimens from 80 patients with pancreatic cancer, Kaplan-Meier analysis showed that patients in the low OLFM4 expression group had a better survival rate than patients in the high OLFM4 expression group. Additionally, multivariate analysis showed that high expression of OLFM4 was an independent prognostic factor predicting poor outcomes. Overall, our study revealed that high expression of OLFM4 was involved in chemoresistance and was an independent prognostic factor in pancreatic cancer. OLFM4 may be a candidate therapeutic target in pancreatic cancer.

Continuous Hemodiafiltration for Pheochromocytoma Crisis with a Positive Outcome

A 38-year-old woman who consulted a local doctor with chief complaints of sudden palpitations, headaches, and chest pain is herein presented. After admission, pheochromocytoma crisis was suspected. Since the patient had a history of acute heart failure and had once survived an episode of cardiac arrest, a rapid decrease in the catecholamine levels was needed. After resuscitation, pharmacological therapy with agents such as phentolamine and landiolol was administered, and continuous hemodiafiltration (CHDF) was performed to reduce the catecholamine levels. Elective surgery was then performed, and a positive outcome was achieved. This case suggests that the preoperative use of CHDF to control pheochromocytoma crisis may therefore be effective.

Abstract 2146: High expression of Olfactomedin-4 correlates with chemoresistance and poor prognosis for pancreatic cancer

Background: Pancreatic cancer has an extremely poor prognosis and novel therapeutic strategies are desperately needed. It is considered that suitable molecules as therapeutic targets are resistant to chemotherapy and correlate with poor prognosis. In this experiment, we aimed to identify the optimal therapeutic targets in pancreatic cancer.

Materials and Methods: We established 10 lines of patient derived xenografts (PDXs) for pancreatic cancer. Next generation sequencer (NGS) analysis was performed for PDXs which were administered chemotherapy and untreated PDXs as a control. Furthermore, we performed immunohistochemistry (IHC) analysis for the protein expression of identified molecules from PDXs and post-operative pathologic specimens from 80 patients with pancreatic cancer. When chemotherapy was added on tumor cell lines forcibly expressing the molecule, antitumor effect was compared with the control.

Results: As a result of NGS analysis, we identified Olfactomedin-4 (OLFM4) molecule which was commonly shown high expression in chemotherapy administered PDXs. In IHC analysis, OLFM4 molecule expression was shown high expression with chemotherapy administered PDXs compared to untreated PDXs. For the analysis to use tumor cell lines forcedly expressing OLFM4 in vitro, the reduction rate of the tumor cell numbers was significantly lower than control vector, even if the concentration of the chemotherapy agent was increased. In a study using tissue specimens of 80 pancreatic cancer patients, Kaplan-Meier analysis showed that low expression of OLFM4 had a better survival rate than patients with high expression (p=0.0926, log-rank test). In multivariate analysis, it was shown that the high expression of OLFM4 was an independent poor prognostic factor with a statistically significant difference (p=0.044, Cox proportional hazards).

Conclusions: It was demonstrated that high expression of OLFM4 was involved in chemoresistance and was an independent prognostic factor for pancreatic cancer. This molecule might be a candidate of therapeutic target in pancreatic cancer.

Citation Format: Ryotaro Ohkuma, Erica Yada, Yutaro Kubota, Kazuyuki Hamada, Hiroo Ishida, Yuya Hirasawa, Hirotsugu Ariizumi, Etsuko Satoh, Junji Tsurutani, Kiyoshi Yoshimura, Tetsuro Sasada, Takeshi Aoki, Masahiko Murakami, Tomoko Norose, Nobuyuki Ohike, Masafumi Takimoto, Takuya Tsunoda, Satoshi Wada. High expression of Olfactomedin-4 correlates with chemoresistance and poor prognosis for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2146.

[Six cases of anaplastic pancreatic carcinoma diagnosed by endoscopic ultrasound-guided fine needle aspiration]

Anaplastic pancreatic carcinoma is a rare form of pancreatic cancer with an extremely poor prognosis. Its diagnosis is often based on surgical specimens and few reports have described the use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis. In this study, we examined six patients (mean age, 70.5 years;sex ratio, 1:1) who were diagnosed with anaplastic pancreatic carcinoma using EUS-FNA. The carcinomas were located in the pancreatic head, body, and tail in one, three, and two patients, respectively. The mean tumor diameter was 49.2mm. Five patients opted for best supportive care due to poor performance status and one underwent chemotherapy (GEM+nab-PTX). The median survival was 40.5 (14-98) days. The characteristic imaging findings of anaplastic pancreatic carcinoma, including central necrosis, marginal contrast enhancement, cystic findings, and internal calcification, were frequently observed in the patients. Anaplastic pancreatic carcinoma can also be diagnosed using biopsy tissue;however, a pathologist's consultation is required to differentiate the disease based on imaging findings for an accurate diagnosis.

An Intra-abdominal Solid-cystic Desmoid That Emerged after Distal Gastrectomy

Desmoid is a locally aggressive fibroblastic neoplasm, typically showing a heterogeneous solid mass, and its pathogenesis is multifactorial, including surgical scars. We herein report a rare case of an intra-abdominal desmoid, consisting of solid and cystic components covered with epithelial linings, that emerged after distal gastrectomy. The preoperative diagnosis was inconclusive, so laparotomy was performed. Histopathology of the solid component showed proliferating spindle cells, which were positive for beta-catenin in their nuclei. Clinicians need to bear in mind that desmoids can appear in a solid-cystic form, and immunostaining of beta-catenin should be applied for tumors that emerge around postoperative wounds.

Molecular alterations associated with metastases of solid pseudopapillary neoplasms of the pancreas

Solid pseudopapillary neoplasms (SPN) of the pancreas are rare, low‐grade malignant neoplasms that metastasise to the liver or peritoneum in 10–15% of cases. They almost invariably present somatic activating mutations of CTNNB1. No comprehensive molecular characterisation of metastatic disease has been conducted to date. We performed whole‐exome sequencing and copy‐number variation (CNV) analysis of 10 primary SPN and comparative sequencing of five matched primary/metastatic tumour specimens by high‐coverage targeted sequencing of 409 genes. In addition to CTNNB1‐activating mutations, we found inactivating mutations of epigenetic regulators (KDM6A, TET1, BAP1) associated with metastatic disease. Most of these alterations were shared between primary and metastatic lesions, suggesting that they occurred before dissemination. Differently from mutations, the majority of CNVs were not shared among lesions from the same patients and affected genes involved in metabolic and pro‐proliferative pathways. Immunostaining of 27 SPNs showed that loss or reduction of KDM6A and BAP1 expression was significantly enriched in metastatic SPNs. Consistent with an increased transcriptional response to hypoxia in pancreatic adenocarcinomas bearing KDM6A inactivation, we showed that mutation or reduced KDM6A expression in SPNs is associated with increased expression of the HIF1α‐regulated protein GLUT1 at both primary and metastatic sites. Our results suggest that BAP1 and KDM6A function is a barrier to the development of metastasis in a subset of SPNs, which might open novel avenues for the treatment of this disease. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Three cases of intracystic papillary neoplasm of gallbladder

Intracystic papillary neoplasm (ICPN) of gallbladder is a comparatively new concept and is described as pre-malignant lesions in Nakanuma et al. (In: Bosman et al. (eds) WHO Classification of Tumours of the Digestive System, World Health Organization of Tumours, IARC, Lyon, 2010). ICPN with high-grade intraepithelial neoplasia is understood to include intraepithelial carcinoma or noninvasive carcinoma. And lesions with invasive cancer components are classified as ICPN with an associated invasive carcinoma [1]. According to Adsay et al., more than half of patients diagnosed with ICPN have invasive cancer components (Adsay et al., Am J Surg Pathol 36:1279-1301, 2012).Polypoid masses in the gallbladder including benign, malignant, and non-neoplastic lesions have been called gallbladder polyps, and ICPN is also a polypoid lesion in the gallbladder. However, it is difficult to differentiate between them. In the literature, it is said that the possibility of malignancy is high in lesions exceeding 1 cm (Terzi et al., Surgery 127:622-627, 2000). And there are few reports on characteristic imaging findings of ICPN.We have experienced three cases (two females and one male) of ICPN and report our imaging findings. Contrast-enhanced computed tomography revealed large papillary polypoid lesions approximately 2-4 cm in size in the gallbladder. Findings suggestive of deformation of the gallbladder wall and extrinsic progression were absent in all cases. T2-weighted magnetic resonance imaging revealed intense signals and diffusion-weighted imaging showed high intensity. Expanding of the gallbladder was seen in case 1, and a tumor stalk-like appearance was seen in the papillary mass in cases 2 and 3. Surgery was performed in all three cases and ICPN was diagnosed pathologically. The cancer was localized to the mucosa, with no infiltration of surrounding tissue in all three cases.

Mucinous Cystic Neoplasms Lined by Abundant Mucinous Epithelium Frequently Involve KRAS Mutations and Malignant Progression

BACKGROUND

Pancreatic and hepatic mucinous cyst neoplasms (MCNs) have a malignant potential, but indolent MCNs are not uncommon.

MATERIALS AND METHODS

The pathological and genetic characteristics of resected MCNs (n=15) categorized by the amount of mucin of the lining epithelium were investigated.

RESULTS

MCNs were divided into two groups: (i) a rich (r)-MCN group (n=6), in which more than half of the epithelium was lined by abundant mucinous epithelium; and (ii) a poor (p)-MCN group (n=9), which consisted of the remaining cases. Three patients in the r-MCN group showed invasive carcinoma or high-grade dysplasia, whereas all patients in the p-MCN group showed low-grade dysplasia. Mutations of Kirsten rat sarcoma viral oncogene homolog (KRAS) were more frequent in the r-MCN group (83%) (p-MCN; 11%, p<0.05).

CONCLUSION

Mucinous MCNs more frequently have KRAS mutations and higher risk of malignant progression.

Immunohistochemical CD73 expression status in gastrointestinal neuroendocrine neoplasms: A retrospective study of 136 patients

The WHO 2010 classification divides gastrointestinal neuroendocrine neoplasms (GI-NENs) into neuroendocrine tumor (NET) G1, NET G2, neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) groups. A total of 136 cases of GI-NENs diagnosed at our hospitals as gastrointestinal carcinoids, endocrine cell carcinomas and NENs over the last 11 years, using the WHO 2010 classification were assessed. Among the 136 cases, 88.2% (120/136) were classified into the NET group (NET G1/G2) and 11.8% (16/136) were classified into the NEC group (NEC/MANEC). The incidences of lymphatic and venous invasions were higher in the NEC group compared with in the NET group (P<0.0001 and P=0.0021, respectively). The immunohistochemical staining of cluster of differentiation 73 (CD73) was evaluated in GI-NENs. CD73 is a potentially useful molecule in tumor immunity. In general, CD73 on the tumor cell membrane converts adenosine monophosphate to adenosine, which restrains the production of interferon-γ and cytocidal activity. Although the association between stem cells of pancreatic NENs and CD73 has been reported, few studies have reported on CD73 expression in GI-NENs. Immunohistochemical CD73 expression on the cytomembrane of neuroendocrine cells was detected in 27.2% (37/136) of the GI-NENs. The positive ratio of CD73 was significantly higher in the NEC group compared with in the NET group (P=0.0015). CD73 is also considered as a potential biomarker of anti-programmed death-1 (PD-1) therapy. The expression of programmed death-ligand 1 (PD-L1) on the cytomembrane of GI-NENs was assessed. The positive ratio of PD-L1 was higher in the NEC group compared with in the NET group (P=0.0011). Furthermore, CD73 expression status was significantly correlated with PD-L1 expression (P<0.0001). These results indicate that CD73 may be an interesting candidate for a biomarker for certain prognostic factors and therapeutics concerning PD-1 therapy.

A case of rectal neuroendocrine carcinoma in a patient with long-standing ulcerative colitis involving alterations of the p16-Rb pathway

The patient was a 54-year-old male who had been suffering from extensive ulcerative colitis (UC) for 17 years. Colonoscopy revealed an elevated lesion in the affected rectum, and its biopsy demonstrated neuroendocrine carcinoma (NEC). The surgical specimen obtained on laparoscopic high anterior resection showed extensive active inflammatory and dysplastic lesions and three grossly visible multifocal malignant lesions: a polypoid fungating tumor of NEC (type 1, 20 mm in diameter, pT3) that had been preoperatively noticed, a polypoid fungating tumor of adenocarcinoma (type 1, 22 mm, pT2) and a protruded sessile polypoid tumor (0-Is, 5 mm, pTis) of adenocarcinoma. The NEC was adjacently accompanied by dysplasia-carcinoma sequential lesions and showed a diffuse immunohistochemical overexpression of p53 and p16 proteins and the loss of Rb with no abnormal immunohistochemical staining of microsatellite instability markers and no KRAS mutations. Fifteen months later, the patient showed liver metastasis from the NEC component, followed by bone and spinal metastasis; he died 22 months after the initial diagnosis. A rare case of lethal NEC arising from long-standing extensive UC was reported. The NEC appeared to be UC-related, not incidental, and complicated by progression from dysplasia to carcinoma involving alterations of the p16-Rb pathway.

Post-cytokine-release Salt Wasting as Inverse Tumor Lysis Syndrome in a Non-cerebral Natural Killer-cell Neoplasm

The pathogenesis of cerebral/renal salt-wasting syndrome remains unknown. We herein present a case of salt-wasting syndrome with a natural killer-cell neoplasm without cerebral invasion. A 78-year-old man with hemophagocytic syndrome received two cycles of chemotherapy that did not induce tumor lysis syndrome, but repeatedly caused polyuria and natriuresis. The expression of tumor necrosis factor-α in the neoplasm led us to hypothesize that an oncolysis-induced cytokine storm may have caused renal tubular damage and salt wasting. Our theory may explain the pathogenic mechanism of cerebral/renal salt-wasting syndrome associated with other entities, including cerebral disorders, owing to the elevation of cytokine levels after subarachnoid hemorrhage.

Ampullary carcinoma is often of mixed or hybrid histologic type: an analysis of reproducibility and clinical relevance of classification as pancreatobiliary versus intestinal in 232 cases

Histologic classification of ampullary carcinomas as intestinal versus pancreatobiliary is rapidly becoming a part of management algorithms, with immunohistochemical classification schemes also being devised using this classification scheme as their basis. However, data on the reproducibility and prognostic relevance of this classification system are limited. In this study, five observers independently evaluated 232 resected ampullary carcinomas with invasive component >3 mm. Overall interobserver agreement was 'fair' (κ 0.39; P<0.001) with complete agreement in 23%. Using agreement by 3/5 observers as 'consensus' 40% of cases were classified as 'mixed' pancreatobiliary and intestinal. When observers were asked to provide a final diagnosis based on the predominant pattern in cases initially classified as mixed, there was 'moderate' agreement (κ 0.44; P<0.0001) with 5/5 agreeing in 35%. Cases classified as pancreatobiliary by consensus (including those with pure-pancreatobiliary or mixed-predominantly pancreatobiliary features) had shorter overall (median 41 months) and 5-year survival (38%) than those classified as pure-intestinal/mixed-predominantly intestinal (80 months and 57%, respectively; P=0.026); however, on multivariate analysis this was not independent of established prognostic parameters. Interestingly, when compared with 476 cases of pancreatic ductal adenocarcinomas, the pancreatobiliary-type ampullary carcinomas had better survival (16 versus 41 months, P<0.001), even when matched by size and node status. In conclusion, presumably because of the various cell types comprising the region, ampullary carcinomas frequently show mixed phenotypes and intratumoral heterogeneity, which should be considered when devising management protocols. Caution is especially warranted when applying this histologic classification to biopsies and tissue microarrays. While ampullary carcinomas with more pancreatobiliary morphology have a worse prognosis than intestinal ones this does not appear to be an independent prognostic factor. However, pancreatobiliary-type ampullary carcinomas have a much better prognosis than their pancreatic counterparts.

Intrapancreatic distal common bile duct carcinoma: Analysis, staging considerations, and comparison with pancreatic ductal and ampullary adenocarcinomas

Distal common bile duct carcinoma is a poorly characterized entity for reasons such as variable terminology and difficulty in determining site of origin of intrapancreatic lesions. We compared clinicopathologic features of pancreatobiliary-type adenocarcinomas within the pancreas, but arising from the distal common bile duct, with those of pancreatic and ampullary origin. Upon careful review of 1017 pancreatoduodenectomy specimens with primary adenocarcinoma, 52 (5%) qualified as intrapancreatic distal common bile duct carcinoma. Five associated with an intraductal papillary neoplasm were excluded; the remaining 47 were compared to 109 pancreatic ductal adenocarcinomas and 133 ampullary carcinomas. Distal common bile duct carcinoma patients had a younger median age (58 years) than pancreatic ductal adenocarcinoma patients (65 years) and ampullary carcinoma patients (68 years). Distal common bile duct carcinoma was intermediate between pancreatic ductal adenocarcinoma and ampullary carcinoma with regard to tumor size and rates of node metastases and margin positivity. Median survival was better than for pancreatic ductal adenocarcinoma (P=0.0010) but worse than for ampullary carcinoma (P=0.0006). Distal common bile duct carcinoma often formed an even band around the common bile duct and commonly showed intraglandular neutrophil-rich debris and a small tubular pattern. Poor prognostic indicators included node metastasis (P=0.0010), lymphovascular invasion (P=0.0299), and margin positivity (P=0.0069). Categorizing the tumors based on size also had prognostic relevance (P=0.0096), unlike categorization based on anatomic structures invaded. Primary distal common bile duct carcinoma is seen in younger patients than pancreatic ductal adenocarcinoma or ampullary carcinoma. Its prognosis is significantly better than pancreatic ductal adenocarcinoma and worse than ampullary carcinoma, at least partly because of differences in clinical presentation. Use of size-based criteria for staging appears to improve its prognostic relevance. Invasive pancreatobiliary-type distal common bile duct carcinomas are uncommon in the West and have substantial clinicopathologic differences from carcinomas arising from the pancreas and ampulla.

Clinical features of gallstone impaction at the ampulla of Vater and the effectiveness of endoscopic biliary drainage without papillotomy

BACKGROUND AND STUDY AIMS

Gallstone impaction at the ampulla of Vater is a critical condition, and the standard treatment is endoscopic papillotomy. However, the clinical features remain largely unclear, and some patients are reluctant to undergo papillotomy because of a bleeding tendency. The aim of this study was to clarify the clinical features of gallstone impaction at the ampulla of Vater and to examine the effectiveness of endoscopic biliary drainage without papillotomy.

PATIENTS AND METHODS

We retrospectively examined 30 patients who had undergone endoscopic treatment for gallstone impaction at the ampulla of Vater between 2010 and 2015.

RESULTS

According to the severity classification for acute cholangitis in the Tokyo Guidelines (TG13), the condition was mild in 8 patients, moderate in 14, and severe in only 8 (27 %), despite the stone impaction at the ampulla of Vater. Hyperamylasemia was observed in 18 patients (60 %); computed tomography (CT) revealed clear pancreatitis in 5 cases (17 %). Patients were classified into Group A (13 patients who received biliary drainage with papillotomy) and Group B (17 patients receiving biliary drainage without papillotomy). All patients in Group B had 1 or more types of hemorrhage risk. There were no differences between the 2 groups in the success rate of biliary drainage, the rate of elevated serum amylase the following day, or procedure-related complications. Serum amylase levels decreased the following day in all patients, even in Group B (including the 10 patients with hyperamylasemia and the 3 patients with clear pancreatitis on CT).

CONCLUSIONS

Even with stone impaction at the ampulla of Vater, typical clinical features of cholangitis and pancreatitis are relatively rare. Biliary drainage without papillotomy is acceptable for gallstone impaction at the ampulla of Vater.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.