Recent investigations have demonstrated a notable increase of certain polysaccharides in the cutaneous lesions of myxedema as compared with normal skin.1-3In the present study Alcian blue (AB), which stains substances believed to be acid mucopolysaccharides,4-6was combined with the periodic acid-Schiff (PAS) stain, which colors 1,2glycols, for the microscopical examination of normal skin and skin from patients with circumscribed or pretibial myxedema, true myxedema, and lichen myxedematosus. Materials and Methods Formalin-fixed specimens6of involved skin from four patients with circumscribed or pretibial myxedema, three with true myxedema, one with lichen myxedematosus, and several of normal skin (all specimens were from adults) were sectioned and treated with the Alcian blue-periodic acidSchiff combination (AB-PAS) according to the technique of Mowry.7 Observations Mowry's fundamental work with Alcian blue alone and in combination with other stains6-8has demonstrated that the AB-PAS combination stains