Increased prevalence of pancreatic neuroendocrine microadenomas in patients with intraductal papillary mucinous neoplasms: yet another example of exocrine-neuroendocrine interaction?

Introduction. Intraductal papillary mucinous neoplasms (IPMN) and neuroendocrine tumors (NET) may develop simultaneously in the pancreas. Neuroendocrine microadenomas (NMA) are precursor lesions for NET. The study aimed to determine the prevalence of NMA/NET in patients with IPMN in a series of resection specimens. Material and methods. Some 232 prospectively gathered specimens were included and examined histopathologically: 51 IPMN, 114 conventional pancreatic ductal carcinomas (PDAC) and 67 ampullary carcinomas (AMPCA). Results. NET were rare in the study samples (single cases among IPMN and AMPCA, and two cases among PDAC). In contrast, NMA were frequently found in IPMN specimens when compared to samples of PDAC and AMPCA (27.45%; 7.89%, and 7.46%, respectively, p < 0.001). Two NMA in IPMN group were related to ducts, but no case of composite (clonal) IPMN/NMA was found. Conclusions. IPMN specimens were enriched in NMA but not in NET. IPMN/NMA association may serve as a model of exocrine-neuroendocrine interaction

The Role of Pathological Method and Clearance Definition for the Evaluation of Margin Status after Pancreatoduodenectomy for Periampullary Cancer. Results of a Multicenter Prospective Randomized Trial

Simple SummaryThere is no clear evidence on the most effective method of pathological analysis and clearance definition (0 vs. 1 mm) to define R1 resection after pancreatoduodenectomy (PD). However, several studies showed that the R1 resection is a poor prognostic factor in patients that have undergone PDs for periampullary cancers. In this randomized clinical trial, specimens were randomized with two pathological methods, the Leeds Pathology Protocol (LEEPP) or the conventional method adopted before the study. The 1 mm clearance is the most effective factor in determining R1 rate after PD but only when adopting the LEEP, the R1 resection represents a significant prognostic factor.Background: There is extreme heterogeneity in the available literature on the determination of R1 resection rate after pancreatoduodenectomy (PD); consequently, its prognostic role is still debated. The aims of this multicenter randomized study were to evaluate the effect of sampling and clearance definition in determining R1 rate after PD for periampullary cancer and to assess the prognostic role of R1 resection. Methods: PD specimens were randomized to Leeds Pathology Protocol (LEEPP) (group A) or the conventional method adopted before the study (group B). R1 rate was determined by adopting 0- and 1-mm clearance; the association between R1, local recurrence (LR) and overall survival (OS) was also evaluated. Results. One-hundred-sixty-eight PD specimens were included. With 0 mm clearance, R1 rate was 26.2% and 20.2% for groups A and B, respectively; with 1 mm, R1 rate was 60.7% and 57.1%, respectively (p > 0.05). Only in group A was R1 found to be a significant prognostic factor: at 0 mm, median OS was 36 and 20 months for R0 and R1, respectively, while at 1 mm, median OS was not reached and 30 months. At multivariate analysis, R1 resection was found to be a significant prognostic factor independent of clearance definition only in the case of the adoption of LEEPP. Conclusions. The 1 mm clearance is the most effective factor in determining the R1 rate after PD. However, the pathological method is crucial to accurately evaluate its prognostic role: only R1 resections obtained with the adoption of LEEPP seem to significantly affect prognosis

Precursor lesions of early onset pancreatic cancer

Early onset pancreatic cancer (EOPC) constitutes less than 5% of all newly diagnosed cases of pancreatic cancer (PC). Although histopathological characteristics of EOPC have been described, no detailed reports on precursor lesions of EOPC are available. In the present study, we aimed to describe histopathological picture of extratumoral parenchyma in 23 cases of EOPCs (definition based on the threshold value of 45 years of age) with particular emphasis on two types of precursor lesions of PC: pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasms (IPMNs). The types, grades, and densities of precursor lesions of PC were compared in patients with EOPCs, in young patients with neuroendocrine neoplasms (NENs), and in older (at the age of 46 or more) patients with PC. PanINs were found in 95.6% of cases of EOPCs. PanINs-3 were found in 39.1% of EOPC cases. Densities of all PanIN grades in EOPC cases were larger than in young patients with NENs. Density of PanINs-1A in EOPC cases was larger than in older patients with PC, but densities of PanINs of other grades were comparable. IPMN was found only in a single patient with EOPC but in 20% of older patients with PC. PanINs are the most prevalent precursor lesions of EOPC. IPMNs are rarely precursor lesions of EOPC. Relatively high density of low-grade PanINs-1 in extratumoral parenchyma of patients with EOPC may result from unknown multifocal genetic alterations in pancreatic tissue in patients with EOPCs

Tissue heterogeneity contributes to suboptimal precision of WHO 2010 scoring criteria for Ki67 labeling index in a subset of neuroendocrine neoplasms of the pancreas

Reporting of Ki67 labeling index (LI) is a routine in diagnostics of neuroendocrine neoplasms of the pancreas. The aim of the study was to examine whether heterogeneity of Ki67 LI distribution in primary tumoral tissue influences precision of reporting of Ki67 LI and Ki67-LI-based grade, both established in adherence to WHO 2010 guidelines. Seventy-one samples of neuroendocrine tumours (NET) and 6 samples of neuroendocrine carcinomas (NEC) of the pancreas were taken for manual counting of Ki67 LI in 25 portions of 100 cells (2500 cells in total) in 3 hot spots an in a single area of lower proliferation rate (cold spot) in each case. Both NET and NEC showed Ki67 LI heterogeneity within primary tumour. Almost 20% of NET showed higher grade when 500 cells rather than 2000 cells were counted in hot spot area. Suboptimal choice of hot spot resulted in under-grading of approximately 20% of NET. Cold spots were constantly present in NET. Heterogeneity of Ki67 LI was also present in NEC, but it virtually never resulted in under-grading. Concept and methodology of Ki67 LI counting in neuroendocrine neoplasms of the pancreas requires clarification. Efforts aiming to improve precision of assessment of Ki67 LI are needed

Hazardous gas areas on high-pressure gas pipelines in poland

Natural gas transmission is strongly connected with fire and explosion safety. Generally, explosion hazard occurs, when at least 5% of natural gas is present in the atmospheric air. As high-pressure gas transmission infrastructure includes many potential sources of gas releases, both operational and accidental, many different cases should be considered. To properly face the potential hazard of explosive atmosphere formation, the hazardous zone should be estimated. There are some guidelines, describing the process of hazardous zones calculating. This paper compares calculations of such hazardous based on Polish and European standards which are also valid in Poland. Calculations are focused on releases that may occur on the safety block and relief valve systems

Standardized grossing protocol is useful for the pathology reporting of malignant neoplasms other than adenocarcinomas

Background: There is no universally accepted protocol for gross examination of pancreaticoduodenectomy specimens. Standardized protocol (SP), known as Leeds Pathology Protocol, was previously validated in pancreatic adenocarcinoma. In this study we aimed to assess usefulness of SP in a series of specimens with pancreatic, ampullary, and duodenal malignant neoplasms other than adenocarcinomas. Materials and methods: SP was based on multi-colour inking and serial slicing of the specimens in a plane perpendicular to the duodenal axis. SP was used in a prospective cohort of 35 neoplasms of neuroendocrine, acinar, and solidpseudopapillary lineage (SP cohort). Surgical margin status, primary tumour stage, and lymph node yield in SP group were compared with corresponding data of a historical cohort of 19 cases examined using nonstandardized protocol (NSP). Samples examined in NSP and SP cohorts were comparable in terms of basic clinical characteristics, median tumour diameter, and distribution of histopathological diagnostic categories. Results: In SP cohort we noticed: (1) higher rate of detection of tumour tissue at surgical margins, (2) more frequent peripancreatic fat tissue invasion, (3) higher percentage of perineural invasion, (4) larger number of lymph nodes retrieved from the specimen, in comparison to NSP group. Application of SP was associated with significantly higher number of tissue blocks taken for histology. Conclusions: SP can be successfully applied for macroscopical examination of pancreaticoduodenectomy specimens with malignant pancreatic, ampullary, and duodenal neoplasms other than adenocarcinomas. SP with proper microscopical diagnosis enables an appropriate schedule of patients with these neoplasms to adjuvant therapy and surveillance programmes