Malignant Rhabdoid Tumour of the Kidney Expressing Neurofilament Proteins: Immunohistochemical Findings and Histogenetic Aspects

Summary A malignant rhabdoid tumour (MRT) of the kidney was studied immunohistochemically using a large panel of monoclonal antibodies. All tumour cells were marked by a vimentin antibody. Variable amounts of the tumour cells were stained by antibodies specific for neurofilament proteins. Keratin, desmin and GFA, however, were not expressed. Antibodies reacting with lymphohaematopoietic antigens as well as with normal renal tissue and renal neoplasms, especially Wilms' tumours, (BA-1, BA-2, BA-3) and an antibody directed against Tamm-Horsfall protein failed to stain the tumour. These results, especially the expression of neurofilaments demonstrated for the first time in a MRT, point to a derivation of the demonstrated tumour from the neural crest. Analysis of the heterogeneous immunohistological marker expression and of the different primary sites of MRTs suggest that these highly malignant neoplasms are a histogenetically heterogeneous group, irrespective of their characteristic light microscopic appearance.