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
Scarring hair loss similar condition. The one exception is Central centrifugal cicatricial alopecia, which primarily affects women of African ancestry and may occur in several women in the same family. While it is possible to have more than one type of hair loss condition, non-scarring forms of hair loss do not turn into scarring forms of hair loss. A scalp biopsy is essential for the diagnosis of cicatricial alopecia and is the necessary first step, as it can be hard to know the diagnosis for sure without a biopsy. Findings of the scalp biopsy, including the type of inflammation present, location and amount