Abstract
Extramammary Paget's disease is a slowgrowing malignant disease occurring on the anogenital area and rarely on the axilla. Recent immunohistochemical studies have shown that Paget cells differentiate to secretory cells of sweat glands. However little is known about the expression of glycosaminoglycan in Paget cells and its relation to the differentiation of sweat glands. Therefore we studied the light and electron microscopic localization of anionic sites stained with cationic gold using postembedding method. We also studied the digestibility of anionic sites with enzymes such as neuraminidase, chondroitinase ABC, and heparitinase, because anionic sites in normal eccrine and apocrine sweat glands show different susceptibility to these enzymes. Cationic gold stained 19.6±3.0% of Paget cells at pH 2.0, although most of these anionic sites were not stained at pH 7.4. Anionic sites in Paget cells were completely digested with neuraminidase, however chondroitinase ABC or heparitinase did not digest them. Enzyme susceptibility and paradoxical pH-dependency of anionic sites in Paget cells were the same as those of apocrine secretory cells and completely different from those of eccrine secretory cells, ductal cells of sweat glands or epidermal keratinocytes. Therefore, the expression of glycosaminoglycan labeled with cationic gold indicates that Paget cells differentiate into secretory cells of apocrine sweat gland.
