Lectin peroxidase conjugate reactivity in acquired cystic disease of the kidney

The origins of acquired cysts, hyperplastic epithelia of cyst walls, and renal cell carcinomas were investigated by evaluating their lectin conjugate reactivity. Paraffin-embedded blocks from 9 patients with acquired cystic disease were examined by the high-sensitivity lectin-antilectin immune peroxidase method. 11-176 lesions in each patient, 690 lesions in total, were stained both with Tetragonolobus lotus lectin (T) and peanut lectin (P); the former is specific for proximal tubules and the latter for distal tubules and collecting ducts. Out of 606 acquired cysts with single-layered epithelia, 559 (92.2%) were positive for T and negative for P, and 66 out of 75 (88.0%) cysts with hyperplastic multilayered epithelia were positive for T and negative for P. Three out of 4 solid adenomas and, to varying degrees, 5 renal carcinomas revealed the same reaction. These results suggest that almost all cysts accompanying acquired cystic disease of the kidney, including those with single-layered and multilayered epithelia, as well as solid adenomas and renal cell carcinomas, are derived from proximal tubules.