Trichilemmal cyst Trichilemmal cyst A trichilemmal cyst, also known as a wen, pilar cyst or isthmus-catagen cyst, is a common cyst that forms from a hair follicle. They are most often found on the scalp. The cysts are smooth, mobile and filled with keratin, a protein component found in hair, nails, skin, and horns. They are, however, clinically and histologically distinct from trichilemmal horns, which are much more rare and not limited to the scalp. Trichilemmal cysts may run in families and they may or may not be inflamed and tender, often depending on whether they have ruptured. Rarely, these cysts may
Hair whorl handedness, whorl orientation, and twin concordance and discordance and (2) that neuronal and visceral (internal organs) forms of bilateral asymmetry are coded by separate sets of genetic pathways. There are many (mostly apocryphal) theories concerning horse behavior and their hair whorls. One paper has suggested that abnormal hair whorls can be used to assess the likelihood of agitated behavior or temperament in cattle in the auction ring. Hair whorl A hair whorl is a patch of hair growing in a circular direction around a visible center point. Hair whorls occur in most hairy animals, on the body as well as