1.8 Cyst

None.

Cyst: a nodule consisting of liquid or semi-solid material surrounded by a capsule located in the dermis. Pseudocyst is different due to lack of capsule/epithelial wall. 

May appear anywhere on body; can be solitary, localized or disseminated.

May progress to infection, necrosis, ulcer or scar.

Epidermoid cyst, trichilemmal cyst, hidradenitis suppurativa, severe acne.

Retention of secretions (epidermoid cyst/trichilemmal cyst).