A rare case of perivascular epithelioid cell tumor (PEComa) of the pancreas diagnosed by endoscopic ultrasound.

A 49-year-old woman consulted her general practitioner (GP) regarding epigastric pain that she had experienced for 2 months. Physical examination and laboratory results were unremarkable. An abdominal ultrasound indicated a solid pancreatic tumor, which was confirmed on subsequent CT and MRI. Endoscopic ultrasound (EUS) showed a well-defined heterogeneous, predominantly hypoechoic mass in the pancreatic body, so a neuroendocrine tumor (NET) was suspected. However, EUS-guided fine-needle aspiration (EUS-FNA) was performed and based on (immuno-)histochemical findings, the extremely rare diagnosis of a perivascular epithelioid cell tumor (PEComa) of the pancreas was made. Due to the malignant potential of pancreatic PEComas, laparoscopic left-sided pancreatectomy was performed. We present a case diagnosed by preoperative EUS-FNA highlighting the clinical and endosonographic features which help to distinguish it from its most important differential diagnosis, neuroendocrine tumors (NETs) of the pancreas.

Potential role of Th17 cells in the pathogenesis of type 2 autoimmune pancreatitis.

Th17 cells have been shown to play an important role in the pathogenesis of a variety of autoimmune diseases. The aim of this study was to investigate the potential role of Th17 cells in autoimmune pancreatitis (AIP). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine gene expression of the signature cytokines of Th17 cells IL-17A and IL-21 and of the Th17 lineage-specific transcription factor retinoic acid receptor-related orphan receptor C (RORC) in human tissue specimens of AIP, classical chronic pancreatitis (CP), and normal pancreas (NP). Infiltrating immune cells were characterized by immunohistochemistry (IHC). Gene expression of IL-17A, IL-21, and RORC were found to be significantly increased in AIP. Accordingly, the number of Th17 cells was significantly increased in AIP compared to NP or CP. Both gene expression analysis and IHC revealed a clear difference between type 1 and 2 AIP. In the periductal compartment of type 2 AIP, which is characterized by granulocytic epithelial lesions (GELs), the number of infiltrating Th17 cells and neutrophilic granulocytes was significantly increased compared to type 1 AIP. Our data suggest that Th17 cells play a role in the pathogenesis of AIP, in particular of type 2 AIP. Cross-talk between Th17 cells and neutrophilic granulocytes mediated via IL-17A may be a potential mechanism by which neutrophils are recruited to the duct and acinar cells with subsequent destruction, a process that is pathognomonic for type 2 AIP.

[Metastasis of pancreatic tumors]. / Metastasierung von Pankreastumoren.

With a 5-year survival rate that has remained stagnant at 6 % for decades, pancreatic ductal adenocarcinoma (PDAC) is still one of the most fatal malignancies. Despite intensive research, currently available therapy options are less than adequate. As more than half of the patients already show distant metastases at the time of diagnosis, metastatic disease should be a primary focus in the development of new therapeutic strategies. New findings from basic research provide various interesting approaches: molecular profiling of the primary tumor seems to be a possible method to gain knowledge about the prognosis, metastatic potential and therapy response of each individual case of PDAC. Certain subpopulations of cancer stem cells also seem to be of importance in metastasis of PDAC and could become potential therapeutic targets in the future. Interactions between tumor cells and their microenvironment are another crucial factor in the metastasis of pancreatic cancer and present various new starting points for potential therapies. As the number of cell types and signaling pathways that are found to play a role in PDAC metastasis continue to grow, the next big challenge will be to translate these findings into viable clinical applications.

[Classification and malignant potential of pancreatic cystic tumors]. / Klassifikation und malignes Potenzial der zystischen Pankreastumoren.

Cystic lesions of the pancreas are increasingly diagnosed with a reported prevalence of 10 % in 70-year-old individuals. Despite their broad spectrum, most resected cystic lesions can be attributed to one of the following entities: intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), serous cystic neoplasms (SCN), neuroendocrine cystic tumors (NECT), and solid pseudopapillary neoplasms (SPN). Among them, IPMN and MCN represent precursors of ductal adenocarcinoma, NECT and SPN are low-grade, potentially malignant lesions, and SCN are usually benign. Due to the not negligible morbidity and mortality rates in pancreatic surgery, even in highly specialized centers, an interdisciplinary preoperative stratification of pancreatic cystic lesions into high- and low-risk tumors is necessary in order to accurately select those cases that need to undergo immediate resection. The role of the pathologist is fundamental in both the preoperative assessment and in the postoperative classification, which determines prognosis, further treatment, and follow-up.

[Intraductal papillary neoplasms of the bile duct (IPNB). Diagnostic criteria, carcinogenesis and differential diagnostics]. / Intraduktale papilläre Neoplasien der Gallenwege (IPNB). Diagnosekriterien, Karzinogenese und Differenzialdiagnosen.

Intraductal papillary neoplasms of the bile duct (IPNB) are rare precursor lesions of intrahepatic and extrahepatic cholangiocarcinoma that follow an adenoma-carcinoma sequence. According to the histomorphology and the distinct immunohistochemical mucin pattern, four different subtypes are recognized: pancreatobiliary, intestinal, gastric and oncocytic. Differential diagnoses include micropapillary lesions (biliary intraepithelial neoplasms), papillary cystic lesions (intraductal tubulopapillary neoplasms) and cystic lesions (mucinous cystic neoplasms).

[Recurrent duodenal ulcer bleeding as the first manifestation of a solid pseudopapillary neoplasm of the pancreas with hepatic metastases]. / Rezidivierte duodenale Ulkusblutung als Erstmanifestation einer hepatisch metastasierten solid-pseudopapillären Neoplasie des Pankreas.

HISTORY AND ADMISSION FINDINGS: In a 17-year-old girl recurrent duodenal ulcer bleeding had led to severe anemia. INVESTIGATIONS: Sonography and computed tomography revealed a partially cystic tumour of the pancreatic head and suspicious hepatic lesions. TREATMENT AND PATHOLOGICAL DIAGNOSIS: A partial duodenopancreatectomy was performed and two liver metastases were resected. Histological examination of the resected pancreatic specimen revealed a solid pseudopapillary neoplasm of the pancreas (SPN) with hepatic metastases. CLINICAL COURSE AND PROGNOSIS: The seven remaining liver metastases were removed in a second procedure (right hepatectomy). One year later two new liver metastases were treated by radiofrequency ablation. Two years after the initial operation, the patient is well and tumor-free. CONCLUSION: SPN is a rare cystic tumor that is mainly found in young women. Direct tumor infiltration of stomach or duodenum can cause gastrointestinal bleedings in rare cases. Resection of the primary tumor and surgical or interventional removal of metastases are the treatment of choice.

[New insights into the origin of pancreatic cancer. Role of atypical flat lesions in pancreatic carcinogenesis]. / Neue Einblicke in die Entstehung des Pankreaskarzinoms. Die Rolle der atypischen flachen Läsionen in der Karzinogenese.

The identification and characterization of precursor lesions is fundamental to develop screening programs for early diagnosis and treatment, aiming at reducing cancer-related mortality. Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease that becomes clinical apparent only in advanced stages. In order to enable screening procedures for early detection of PDAC, an exact characterization of precursor lesions is of utmost importance. Pancreatic intraepithelial neoplasias (PanIN) are the most frequent and best characterized precursors of PDAC and are lesions with a ductal phenotype thus indicating a ductal cell origin of PDAC. However, evidence from genetically engineered mouse models suggests that tubular complexes (TC) originating through a process of acinar-ductal metaplasia (ADM) form atypical flat lesions (AFL) that may represent an alternative pathway of pancreatic carcinogenesis. Based on a thorough morphological and genetic analysis of murine TC, AFL and PanIN and their human counterparts, a new dual model of pancreatic carcinogenesis is proposed taking into account the role of AFL as possible new precursors of PDAC.

[Pathology and classification of intraductal papillary mucinous neoplasms of the pancreas]. / Pathologie und Klassifikation intraduktaler papillär muzinöser Neoplasien des Pankreas.

Intraductal papillary mucinous neoplasms (IPMN) are precursor lesions of ductal adenocarcinoma of the pancreas and one of the most common cystic entities in this organ. Branch and main duct types are further distinguished based on the tumor localization. An additional classification is based on the predominant architecture and immunohistochemical profile with four prognostic relevant subtypes, gastric, intestinal, pancreato-biliary and oncocytic. This review provides an overview about the malignant potential of the different subtypes and the prognosis of associated invasive tumors and gives recommendations for the pathological assessment of resection specimens with IPMNs.

Parkin gene variations in late-onset Parkinson's disease: comparison between Norwegian and German cohorts.

OBJECTIVES: Mutations in the Parkin gene can cause autosomal recessive early-onset Parkinson's disease (PD). Recently, Parkin mutations were also suggested to play a role in the commoner late-onset forms of PD. METHODS: We compared a German cohort of PD patients (95) with a Norwegian cohort of PD patients (96). Both cohorts have predominant late-onset form of PD. Mutation and polymorphism frequencies were compared via single-strand conformation polymorphism and sequence analyses. RESULTS: Three heterozygous missense mutations (Arg256Cys, Arg402Cys and Thr240Met) were found in late-onset PD patients in the German patient cohort (1.6%). A missense mutation (Arg402Cys) was also found in one of 149 healthy control subjects (0.3%). Only one heterozygous missense mutation (Arg256Cys) was identified in a Norwegian patient suffering from late-onset PD (0.5%). The frequencies of four known single nucleotide polymorphisms significantly differ between the two distant European populations. CONCLUSION: The results support the hypothesis that heterozygous mutations in the Parkin gene may act as susceptibility alleles for late-onset forms of PD in rare cases.