Cytologic, histologic, DNA ploidy and electron microscopic analyses of a case of vulvar Paget's disease

The cells in a case of multifocal vulvar Paget's disease were studied by cytology, histology, ploidy analysis and electron microscopy. The Paget cells in smears were seen in an isolated or a sheetlike arrangement. The cells had peripherally located nuclei, prominent nucleoli and unevenly distributed melanin granules of various sizes in their cytoplasms. The histologic sections contained multifocal microscopic lesions that were larger than the macroscopic lesion. Paget cells in the histologic sections demonstrated positive cytoplasmic staining with the periodic acid-Schiff, Alcian blue, mucin, glandular cytokeratin, epithelial membrane antigen and carcinoembryonic antigen reactions. The nuclear DNA histogram of the Paget cells in the cytologic smears showed a polyploid pattern, with a sharp peak at 4c; the cells in sheets had a ploidy level between 2c and 4c while a few of the isolated cells had a ploidy level that extended past 8c. Various nuclear DNA patterns were observed in the histologic samples; a recurrent lesion was later found in an area adjacent to the primary lesions that had higher ploidy levels. Ultrastructurally, the Paget cells contained lysosomes and tiny electron-dense secretory granules in their cytoplasms, suggestive of a glandular cell origin. These findings suggest that Paget cells may be derived from the secretory portion of sweat glands.