Without examination, confirmation of a
diagnosis is tough but it can be a
sebaceous cyst or a
cutaneous horn. A
sebaceous cyst is a
closed sac occurring just under the skin which contains a "pasty" or "cheesy" looking substance called keratin.They may occur anywhere on body but scalp, ears, back, face, and upper arm, are common sites for sebaceous cysts.
A cutaneous horn is a conical projection above the surface of the skin that resembles a miniature horn.