An epidermal cyst is a type of slow-growing lump underneath the skin. This cyst contains soft, cheese-like skin contents. These usually appear on the face, neck, chest, upper back, genitals, or behind the ears. Similar cysts called pilar cysts often occur on the scalp.

Causes include:

  • Blockage of a hair follicle by skin cells—When an injury to the skin occurs, cells from the surface may block hair follicles located deeper within the skin.
  • Damage to a hair follicle due to acne
  • Blockage or defect of the sebaceous gland—This gland is near the hair follicle. It secretes oily material used to lubricate the skin and hair.
Hair Follicle
si1844_96472_1
Copyright © Nucleus Medical Media, Inc.