Histopathologic features of the skin of hairless newborn pigs with goiter.

The skin of 15 hairless newborn pigs with parenchymatous goiter was studied histopathologically. Most of the lesions were in the hair follicles; follicles were scarce and reduced in size, contained slender hairs, and revealed a shortage of penetration into the hypodermis. Hair follicles in the immature stages, hair pegs, and germs also were recognized, with the thin epidermis lacking in keratinization. It was felt that these changes resulted from a retardation of cellular differentiation of the germinal layer. In view of these findings, skin lesions were regarded as hypoplasia of hair.