[EUS-FNA: how to improve biopsy results? An evidence based review]. / EUS-geführte Feinnadelbiopsie (EUS-FNP): Wie gelingen gute Biopsien? Eine evidenzbasierte Analyse.

Endosonography with fine-needle aspiration biopsy (EUS-FNA) has become a widespreadly available clinical tool to diagnose numerous different lesions in humans. EUS-FNA is frequently used for tissue-based diagnoses such as lymphatic diseases (ranging from tuberculosis / sarcoidosis to malignant lymphoma) or solid tumors (such as pancreatic carcinoma, neuroendocrine tumors, sub-epithelial gastrointestinal tumors and others). Outcomes of EUS-FNA results, however, vary which is caused by several different factors ranging from experience of the endoscopist over technical factors such as use of stylet or suction for puncture through the skills of the cyto-pathologist who takes care of the specimen obtained by EUS-FNA. Though introduced since more than 20 years ago EUS-FNA has still not yet been perfectionized and several issues remain controversial among endoscopist. These issues include needle size and type (FNA versus TNB needles), use of a stylet and suction for FNA sampling, pure cytologic assessment versus cyto-histologic techniques, grading of the investigator´s and pathologist´s experience and improvement of EUS training for novices. In this report we briefly review the actual literature and summarize the available evidence on some controversely discussed issues. The results support the view that use of a stylet rarely aids to increase the amount of tissue obtained during EUS-FNA, whereas use of suction can be helpful in certain situations. Novel cutting needles may potentially improve number and size of core biopsies that can be rendered for special histologic tissue processing techniques. An in-room-cytopathologist not necessarily improves outcome of EUS-FNA results but may have a role during build-up of EUS units to become more successful. EUS-FNA education requires skilled endoscopists on both sides and can presumably be improved by objective testing of practical expertise by peer review and introducing objective sampling parameters. Novel techniques and equipment are about to evolve in the near future.

Mammary gland specific hEGF receptor transgene expression induces neoplasia and inhibits differentiation.

The epidermal growth factor receptor (EGFR) is overexpressed in about 48% of human breast cancer tissues. To analyse the role of the EGFR in mammary tumor development we generated transgenic mice expressing the human EGFR under the control of either the MMTV-LTR (MHERc) or the beta-lactoglobulin promoter (BLGHERc). The BLGHERc-transgene was expressed exclusively in the female mammary gland, whereas the MHERc transgene was expressed more promiscuously in other organs, such as ovary, salivary gland and testis. Female virgin and lactating transgenic mice of both strains have impaired mammary gland development. Virgin EGFR transgenic mice developed mammary epithelial hyperplasias, whereas in lactating animals progression to dysplasias and tubular adenocarcinomas was observed. In both strains the number of dysplasias increased after multiple pregnancies. The transgene expression pattern was heterogeneous, but generally restricted to regions of impaired mammary gland development. Highest EGFR transgene expression was observed in adenocarcinomas. By using a whole mount organ culture system to study the differentiation potential of the mammary epithelium, we observed a reduced number of fully developed alveoli and a decrease in whey acidic protein expression. Taken together, EGFR overexpression results in a dramatic effect of impaired mammary gland development in vitro as well as in vivo, reducing the differentiation potential of the mammary epithelium and inducing epithelial cell transformation.