Pancreatic mucinous noncystic (colloid) carcinomas and intraductal papillary mucinous carcinomas are usually microsatellite stable.

Pancreatic mucinous noncystic (colloid) carcinomas (MNCC) differ from the usual ductal adenocarcinomas in their mucin expression profile and share with many extrapancreatic mucinous carcinomas the expression of MUC2. Because mucinous carcinomas are frequently associated with mutations of the DNA mismatch repair genes, causing them to exhibit the so-called mutator phenotype, we decided to investigate whether MNCCs of the pancreas are characterized by microsatellite instability (MSI). Twelve carcinomas with a mucinous phenotype (8 mucinous noncystic carcinomas, 3 intraductal papillary-mucinous carcinomas with an invasive muconodular component, and 1 ductal adenocarcinoma with an extensive mucinous noncystic component) and 11 ductal adenocarcinomas were immunostained with monoclonal antibodies to the mismatch repair gene products hMLH1, hMSH2, and hMSH6.

A comprehensive characterization of pancreatic ductal carcinoma cell lines: towards the establishment of an in vitro research platform.

There are a large number of stable pancreatic ductal carcinoma cell lines that are used by researchers worldwide. Detailed data about their differentiation status and growth features are, however, often lacking. We therefore attempted to classify commonly used pancreatic carcinoma cell lines according to defined cell biological criteria.

Intra-arterial instillation of microencapsulated, Ifosfamide-activating cells in the pig pancreas for chemotherapeutic targeting.

Background: The therapeutic efficacy of intratumoral instillation of genetically engineered, CYP2B1-expressing, microencapsulated cells in combination with ifosfamide had been previously demonstrated in xenografted human pancreatic ductal carcinomas [Gene Ther 1998;5:1070-1078]. Prior to a clinical study, the feasibility of an intra-arterial application of microencapsulated cells to the pancreas and its consequences to the organ had to be evaluated.

Material And Methods: Microencapsulated, CYP2B1-producing cells were instilled both in vivo (transfemoral angiographical access) and in vitro (perfusion model) in the splenic lobe of the pig pancreas.

Tumor-suppressing pathways in cystic pancreatic tumors.

Introduction And Aims: Serous and mucinous cystic pancreatic tumors have different clinical behavior. We evaluated whether they also have genotypic differences by analyses of the tumor suppressor genes, p16INK4a, p53, and DPC4.

Methodology: Seven serous cystadenomas (SCA) and seven malignant mucinous cystadenocarcinomas (MCC) were analyzed for alterations in the tumor suppressor genes p16INK4a, p53, and DPC4 by single-strand conformational variant analysis, direct sequencing, and immunohistochemical analysis.

Vascular endothelial growth factor mediated angiogenic potential of pancreatic ductal carcinomas enhanced by hypoxia: an in vitro and in vivo study.

Angiogenesis in pancreatic ductal adenocarcinomas depends on the presence of angiogenic factors such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and is thought to be stimulated by hypoxia. We tested the angiogenic potential of 9 cell lines of pancreatic ductal carcinoma origin by screening mRNA and protein expression of VEGF and bFGF and the release of VEGF into culture medium under normoxic and hypoxic (5% or 0.2% O2) conditions.

Xenin-immunoreactive cells and extractable xenin in neuroendocrine tumors of duodenal origin.

Background & Aims: Xenin is a 25-amino acid peptide produced by specific endocrine cells of the duodenal mucosa. We investigated whether xenin is expressed in neuroendocrine tumors.

Methods: Seventy-two foregut and midgut neuroendocrine tumors were examined by means of immunohistochemistry, confocal laser microscopy with an antibody against the C-terminus of xenin, and high-pressure liquid chromatography after acidic extraction, assessed by radioimmunoassay.

Gastrointestinal mesenchymal tumors - immunophenotypic classification and survival analysis.

The current definition of gastrointestinal tumors (GIST) as CD117-positive mesenchymal tumors of uncertain malignant potential fails to include a number of cases with similar histology. In an attempt to improve the classification of these neoplasms, we conducted an immunohistochemical analysis of 244 mesenchymal tumors with histological features of GIST. According to their immunophenotype, the tumors were classified as GISTs, which are characterized by CD117 (c-kit) expression; gastrointestinal CD117-negative CD34 positive stromal tumors (GINST); alpha-smooth muscle actin and/or desmin positive gastrointestinal leiomyogenic tumors (GILT); S-100 and glial fibrillary acidic protein positive gastrointestinal glial/schwannian tumors (GIGT); gastrointestinal neuronal/glial tumors (GINT), which are positive for S-100/glial fibrillary acidic protein plus neuronal/glial markers; and gastrointestinal fibrous tumors (GIFT), which are only vimentin positive.

Chronic sclerosing sialadenitis of the submandibular gland is mainly due to a T lymphocyte immune reaction.

The aim of our study was to investigate the role of immunopathological processes in the pathogenesis of chronic sclerosing sialadenitis of submandibular glands (Küttner tumor). For this purpose, biopsy specimens from submandibular glands of 22 patients with the histological diagnosis of chronic sclerosing sialadenitis were analyzed. Paraffin-embedded tissues were immunostained for T-lymphocyte subsets (CD3, CD4, CD8), cytotoxic T cells (granzyme B), B cells (CD20, Ki-B3), and macrophages (Ki-M1P).

Focal and Diffuse Beta Cell Changes in Persistent Hyperinsulinemic Hypoglycemia of Infancy.

In recent years our understanding of the changes in the endocrine pancreas in persistent hyperinsulinemic hypoglycemia in infancy, a form of congenital hypoglycemia, has increased considerably, in terms of both morphological classification and molecular pathogenesis. This review summarizes the current state of knowledge about the pathological lesions in the pancreas and their relationship to recently reported molecular findings.

Neoplasms Causing Nonhyperinsulinemic Hypoglycemia.

Non-islet cell tumor hypoglycemia (NICTH) is uncommon. Many of the tumors associated with NICTH are mesenchymal tumors, although carcinomas are also involved in some cases. High serum levels of insulin-like growth factor II (IGF-II) have been associated with NICTH.

Acinar cell cystadenoma of the pancreas: a new entity?

This report describes a newly observed cystic lesion of the pancreas showing acinar cell differentiation. The patients affected by this lesion included seven women and three men (age range 16-66 years). In six patients, all of whom were female and all but one of whom suffered from abdominal pain, the cystic lesions (diameters, 4-15 cm) were detected by imaging techniques and subsequently removed.

How do gastric carcinoma classification systems relate to mucin expression patterns? An immunohistochemical analysis in a series of advanced gastric carcinomas.

Gastric carcinoma classifications differ in their value for distinguishing tumors according to their morphological pattern, functional properties, and biological significance. In this study we evaluated which of three established classification systems is best correlated with the expression patterns of certain mucins. A total of 160 gastric carcinomas from Turkey and Germany were screened immunohistochemically for the expression of MUC1, MUC2, MUC5AC, and MUC6, and the results were related to the different tumor categories in Lauren's, Carneiro's, and Goseki's classifications.

Lymphoepithelial cysts of the pancreas: a report of 12 cases and a review of the literature.

Lymphoepithelial cyst (LEC) of the pancreas is a rare lesion of undetermined pathogenesis that had been documented almost exclusively in males. The literature on this entity is limited to reports of single or small numbers of cases. Here is presented a clinicopathologic analysis of 12 patients with LEC, 4 of whom were female.

Neuroendocrine carcinomas of the prostate and urinary bladder: a diagnostic and therapeutic challenge.

This review addresses the various morphological, immunohistochemical and cell kinetic aspects of pure and mixed neuroendocrine carcinomas of the prostate and urinary bladder and of carcinomas with focal neuroendocrine differentiation. It is important that neuroendocrine tumours of the prostate and urinary bladder be clearly distinguished from their nonneuroendocrine counterparts because of differences in treatment and prognosis. In the case of high-grade neuroendocrine carcinomas, early diagnosis and initiation of appropriate chemotherapy may increase survival and potentially induce complete remission in individual cases.

Mucinous nonneoplastic cyst of the pancreas: a novel nonneoplastic cystic change?

Cystic lesions and neoplasms of the pancreas are uncommon, but they are of special interest because they can usually be cured by resection. During the last decade, the spectrum of these tumors has increased considerably. We present a series of five cystic lesions of the pancreas that differ from all categories described so far.

Insulin-Dependent Diabetes Mellitus: Islet Changes in Relation to Etiology and Pathogenesis.

Type and type II diabetes are the most common types of diabetes. The ratio of type I to type II diabetes is about 1:9. Type I diabetes is caused by absolute insulin deficiency and is therefore referred to as insulin-dependent diabetes.