An analysis of histology and DNA-ploidy in primary wilms tumors and their metastases and a study of the morphological effects of therapy.

In children with Wilms' tumours the length of survival is greatly influenced by success in preventing or controlling metastatic disease. The current study focuses on the morphological aspects of metastases when compared with the primary tumour. In 8 patients it appeared that blastema is the most likely component to metastasize, whereas epithelial and stromal components were hardly, if at all, represented in metastases. Furthermore, flow cytometric DNA ploidy determinations on 4 cases showed that both the primary tumours and the metastases had stemlines in the diploid and low aneuploid (hyperdiploid) range. Finally, in four cases the influence of therapy on morphology of the primary tumours was analyzed. In these cases blastema seemed to be the component most sensitive to therapy. Thus, blastema seems to play a central role in prognosis of Wilms' tumours; either reacting to therapy or, if insensitive, by metastasizing.