KIT expression in fetal, normal adult, and neoplastic renal tissues

Background: KIT is a transmembrane tyrosine kinase receptor, expressed in high amounts in various normal cells. In addition, c-kit mutation or activation is a major pathogenetic event in certain tumours (such as gastrointestinal stromal tumours). There are only limited data in the literature on the expression of KIT in normal and neoplastic renal tissues. Aims: To investigate KIT expression in normal and neoplastic renal tissues. Methods: KIT expression was evaluated by means of immunohistochemistry in paraffin wax embedded sections from 67 tissue samples. Results: Eight of eight fetal kidneys, and 10 of 10 normal adult kidneys revealed cytoplasmic staining of renal tubules. The three cases of renal dysplasia studied expressed KIT in their normal and aberrant tubules. Two of 13 conventional renal cell carcinomas (RCCs), two of seven papillary type RCCs, four of seven chromophobe type RCCs, none of six nephroblastomas, seven of seven oncocytomas, two of two mesoblastic nephromas, and two of four angiomyolipomas were positive. Conclusion: KIT is expressed in normal fetal and adult renal tubules, and in a subset of renal tumours. The expression of KIT in these renal tumours may prove to have diagnostic relevance and/or therapeutic implications

The hard way from bench to bedside history lessons from the pathogenesis of idiopathic membranous nephropathy (mn)

Membranous nephropathy (MN) is one of the most common causes of adult nephrotic syndrome. Histopathology involves typical subepithelial immuncomplexes, with an obvious pathogenetic role. Today, the study of pathogenesis, which began in 1959, has proven that MN is an organ-specific autoimmune disease. Our aim was to follow and draw some historical lessons from this 60-year long course of studies on MN. Heymann nephritis (HN; 1959) is the classical animal model, in which the pathogenetic role of immuncomplexes in MN was first established. HN is induced by injection in rats of tubules brush border (BB) antigens (active HN) or the corresponding antibodies (anti-BB; passive HN). In 1978, lesions of HN forming ex vivo after anti-BB injection in an isolated perfused rat kidney model, i.e. in the absence of circulating BB antigens, proved that immune-complex formation occurs in situ. In 1982, megalin was identified as the epithelial auto-antigen in HN. However, as megalin could not be detected in human podocytes, pathogenesis of human MN still remained unresolved. In 2002, neutral endopeptidase was identified as the podocyte antigen in cases of antenatal alloimmune human MN, clearly implicating the pathogenetic role of podocyte membrane proteins and in situ immune-complex formation. In the next years, phospho-lipase A2-receptor and Thrombospondin type-1 domain containing 7A were identified as organ-specific auto-antigens associated with MN. The maxim “sciencia facit altus” could precisely describe the evolution of 60 years of research on the pathogenesis of MN, which was decisively promoted with the breakthroughs made in the last 20 years. This pattern may change as we reach the exciting new scientific era. © Athens Medical Society

Fine Needle Aspiration Cytology of a Primary Malignant Peripheral Nerve Sheath Tumor Arising in the Parotid Gland A Case Report

Background Malignant peripheral nerve sheath tumor (MPNST) is an uncommon mesenchymal neoplasm showing nerve sheath differentiation, usually arising in large nerves of the trunk and extremities. Prima)), location in the parotid gland is rare. We describe fine needle aspiration (FNA) findings ill a Case of MPNST ill the parotid gland. Differential diagnostic problems encountered in interpretation are discussed. Case A 39-year-old wan underwent FNA Of a well-circumscribed, painless, mobile mass of the parotid gland. Smears were cellular, with clusters tightly packed spindle or oval cells arranged in a storiform or whorled pattern, showing clearly malignant features. Elongated nuclei with tapered ends and many angulated nuclei were encountered. The background contained abundant necrotic material with dispersed malignant nuclei. Neoplastic cells were positive for vimentin and weak), positive for S-100 and negative for cytokeratins 8 and 18 and HMB-45. Cytologic diagnosis was positive for malignant cells consistent with a spindle cell sarcoma, with morphologic features compatible to neural differentiation, confirmed by histologic examination. Conclusion This case illustrates that attention to morphologic criteria suggestive of nerve sheath phenotype supported by immunocytochemical data is extremely helpful and reliable in the diagnostic approach to MPNSTs, men in rare locations. (Acta Cytol 2009;53:423-426

The Fat Content of Small Primary Breast Cancer Interferes with Radiofrequency-Induced Thermal Ablation

Background: Radiofrequency (RF) thermal ablation is a minimally invasive technique of local mass elimination with variable efficiency. Methods: Ten patients with small primary breast cancer diagnosed preoperatively by core needle biopsy were ablated percutaneously by an RF (Radionics Cool-tip) device operating on impedance control mode. The percent fat-containing area was calculated in each slide of a total of 47 slides introduced to IQ materials software image analysis. Results: Seven of 10 tumors with tumor diameter less than 2.8 cm and fat content less than 12.47% were totally ablated ( score 3). One of 10 with 3 cm tumor diameter and 5.45% fat content showed an intermediate degree of ablated tissue ( score 2), and the last 2 with 2 cm and 2.2 cm tumor diameter and more than 19.74% tumor fat content were minimally ablated ( score 1). Our present exploratory study on 10 patients suggests dependence of the degree of thermal damage on tumor fat content. Conclusions: We conclude that the fat content of small primary breast cancer could serve as a 'heat sink' and should be considered as a preventing factor of complete local tumor destruction by RF thermal ablation. Copyright (c) 2008 S. Karger AG, Base