Fissures and ridges
Fissures (invaginations or sulci) are commonly seen in seborrheic keratosisThis glossary term has not yet been described. and may also be seen in melanocyticThis glossary term has not yet been described. neviThis glossary term has not yet been described. with congenital pattern. In essence, fissures are linear grooves in the epidermis and, like comedo-like openings[[Comedo like openings]], correspond to surface invaginations. A pattern that resembles “brain-like appearancelines, curved and thick to describe the pattern and fissures and ridges (former synonyms “gyry and sulci” and “fat fingers”) to describe the structural components of the pattern SK” or cerebriform appearance is created, with the grooves resembling “sulci” and the intervening ridges resembling surface “gyri”. Fissures correspond histopathologically to wedgeshaped, keratin-filled invaginations of the epidermis.