Sebaceous cyst
- Epidermal cysts
- Commonest type of cystic skin lesion
- Occur as a result of growth of epidermal cells in dermis to cause occlusion of follicles
- Histological subtypes
- Epidermal cyst: arise from infundibular portions of hair follicles
- Trichilemmal cysts: arise from hair follicle epithelium and are most common in scalp
- Complications
- Infection - associated discharge
- Ulceration
- Calcification: trichilemmal cysts - may cause the cyst to feel hard on palpation
- Sebaceous horn formation: hardening of slow discharge of sebum from a wide punctum
- Malignant change