[Injury patterns in interstitial lung diseases]. / Schädigungsmuster interstitieller Lungenerkrankungen.

Interstitial lung diseases (ILD) consist of a complex group of hundreds of non-neoplastic pulmonary diseases with divergent clinical presentation, morphology and progression tendency. This great number of clinical entities contrasts with a limited number of injury patterns. By definition, an adequate classification requires a synopsis of the clinical, radiological and morphological findings. The ATS/ERS (American Thoracic Society/ European Respiratory Society) guidelines recommend an open lung biopsy if high-resolution computed tomography does not provide conclusive results. Due to the focal nature and overlapping features of injury patterns, microscopic categorization is not always possible. In order to broaden the diagnostic criteria by using molecular patterns the Lung Research Working Group of the Institute of Pathology of Hannover Medical School, Europe's leading transplant center, is working up fresh explanted human lungs in a standardized manner. These fresh specimens are used for translational research by means of functional, morphological and molecular techniques in order to identify disease-specific regulatory processes and to make them usable diagnostically and therapeutically.

Role of immunohistochemistry and fluorescence in-situ hybridization (FISH) in the diagnosis of spindle and round cell tumors of the kidney.

UNLABELLED: Spindle cell/mesenchymal tumors of the kidney are rare. The diagnosis is supported mainly by the application of ancillary techniques such as immunohistochemistry (IH) and in-situ hybridization (FISH). An accurate diagnosis is essential because early management by complete resection and adjuvant chemotherapy improves the prognosis dramatically. Synovial sarcoma and primitive neuroectodermal tumor/Ewing sarcoma are infrequent malignancies which usually present in soft tissues but rarely in the kidney. The challenge for the pathologists is to histologically differentiate between different types of sarcomas such as PNET/Ewing's sarcoma, sarcomatous dedifferentiated renal cell carcinoma, metastasis, non-Hodgkin's lymphoma, nephroblastoma and angiomyolipoma. METHODS: We report from our experience six exemplary rare cases that presented in the kidney as spindle/round cell tumors. RESULTS: We have arrived at the accurate diagnosis after performing a large panel of IH and FISH. CONCLUSION: In summary we advise an immunohistochemical panel for round/spindle cell tumors of the kidney and for unclear cases we advise to add (FISH) to get the correct diagnosis, as they are completely different regarding surgical approach and post-operative adjuvant therapy.

Overview and evaluation of the value of fine needle aspiration cytology in determining the histogenesis of liver nodules: 14 years of experience at Hannover Medical School.

Fine needle aspiration (FNA) is a sensitive and specific method (95%), often helpful in characterizing suspected liver lesions. It is appropriate to distinguish between primary and secondary liver neoplasia. Moreover, in most cases, the use of cell block preparations of small specimens allows immunocytochemical evaluation to determine the nature of the primary tumour. In a retrospective study at Hannover Medical School (MHH) from 1998 to 2012 (14 years), 4,136 sonographically guided FNAs were performed. The patients provided consent and the study protocol was approved by the local ethics committee. There were 39.6% malignant and 57.5% benign lesions in the liver, while 2.8% of the cases were undetermined. FNA was non-representative in 1.1% of the cases. The diagnostic utility of highly differentiated hepatocellular carcinoma (HCC; G1) remains difficult; cell bridges with cell atypia are pathognomonic for diagnosis. Ancillary techniques and immunocytochemical investigations will increase the sensitivity and specificity, particularly by using the cell block technique.