Expression of CA15–3 in renal cell carcinoma

CA15–3 expression was analyzed in renal cell carcinoma (RCC) from the standpoint of the histogenesis of RCC. Tissue sections from surgical specimens of 12 cases of clear cell type RCC and from autopsy specimens of eight fetal kidneys were stained by an indirect immunoperoxi-dase method using DF-3. All the RCC cases stained positively for CA15–3, with 10 of the 12 cases showing strong, diffuse immunoreactivity on the cell membrane. Expression of CA15–3, as well as other markers such as epithelial membrane antigen, neuron-specific enolase, glandular cytokeratin and other lectins, suggest a more complicated histogenesis of RCC, rather than a simple proximal tubular origin.