[Classification, histochemistry and ultrastructure of experimental renal tumors (author's transl)]

The experimental Cycasin-adenomas of the Wistar rats can be classified into basophilic, eosinophilic, and oncocytic and, according to the histoarchitecture, in solid and cystopapillary forms of growth. In this sense they correspond morphologically with the adenomas in man and can serve the comparative pathology. Morphogenetically they develop from tubular islets of proliferation or cysts. This fact broadens our observations about relative homogeneous morphological forms of growth in man and animal. At the same time the assumption of direct carcinogenic effect on the tubulus cells in animals is confirmed. The adenomas are also enzyme-histochemically and electronmicroscopically different. According to the present findings, additional clear subclassifications are only possible with great difficulty. On the basis of its light microscopical identical structure, it could be assumed that the renal adenomas of the human have a similar enzyme-chemical and ultrastructural state.