[Cysts of the hepatoid glands]

Cysts are specific rounded closed structures characteristic of some hepatoid glands. They never occur in other cutaneous glands of mammals. The cysts of the circumanal hepatoid glands of the dog and polar fox, the violet gland of the polar and common red fox, and the groin pouches of three species of gazelles were studied. The cyst is enclosed in a cellular wall saturated with glycogen. The amorphous content of the cyst is rich in hydrophobic lipids and it also contains protein. The cysts of the dog and gazelle contain also carboxylated mucopolysaccharides. The amorphous masses of the cyst are surrounded by concentric fibers rich in sulfated mucopolysaccharides. It was shown, using the circumanal glands of adult male dogs, that cysts are permanently formed from single secretory cells capable of synthesizing hydrophobic lipids before their destruction. During the involution of the hepatoid cysts (circumanal glands of an old female dog), whole acini and glandular lobes transform into cysts.