Metachromasia in the Human Prostate: A Histochemical Difference Between Benign Prostatic Hyperplasia and Prostatic Carcinoma

Metachromasia is a histological staining reaction in which a dye is changed by the tissue from its original to a contrasting color. With toluidine blue at a pH of 8.3 or 3.8 metachromatic staining is seen in the tissue of benign prostatic hyperplasia. When adenocarcinoma is adjacent to or even within the prostate containing benign hyperplasia, no metachromasia is seen around the benign acini. No such staining was seen in glands examined that contained either well differentiated or moderately well differentiated adenocarcinoma. No metachromatic periacinar staining was noted in the normal prostate. This observation may provide information as to the morphogenesis of prostatic hyperplasia.