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.

Standardized processing of native tissue in breast pathology.

In breast surgery, replacement of intraoperative frozen section by core needle and vacuum biopsies hampers collections of unfixed breast specimens. We practice immediate intraoperative macroscopic analysis of resection margins and vacuum-cooling of breast specimens to enable native tissue asservation for assessment of biological markers and tissue banking of tumor tissue. In addition, slicing of native tissue before formalin fixation guarantees a standardized and uniform fixation. Starting in 2013, more than 350 breast specimens were processed as native specimens in the Institute of Pathology of Hannover Medical School. Breast specimens with an invasive carcinoma and request of an intraoperative resection margin assessment were processed with an immediate intraoperative pathological analysis. All other breast specimens without assessment of an intraoperative resection margin were vacuum-fixed processed. In all cases, native tissue for biomarker analyses and tumor banking could be preserved.

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.

[Intraoperative pathological rapid investigations in breast surgery]. / Intraoperative pathologische Sofortuntersuchung in der Mammachirurgie.

In breast surgery intraoperative frozen sections for the diagnosis of malignancy has lost impact and has largely been replaced by preoperative core needle biopsies. Nevertheless, there is still need for immediate pathological investigation of native breast tissue during surgery due to three reasons: (1) macroscopic and microscopic evaluation of resection margins, (2) the histological analysis of sentinel lymph nodes in order to circumvent secondary axillary surgery and (3) the preparation of native tissue for tumor banking or measurement of biomarkers. Because histology provides only a facultative component of immediate pathological examination of breast specimens during surgery, the term frozen section does not seem to be appropriate anymore. Intraoperative evaluation of resection specimens by pathologists provides surgically relevant information immediately, guarantees standardized preparation and fixation of specimens and enables tissue banking of native tissue for assessment of biological markers.