Sebaceous Cyst

A sebaceous cyst is a lump in the skin which originates from hair follicle and is also called ‘epidermoid cyst or ‘pilar’ cyst. Unlike common belief, a sebaceous cysts do not form due to the blockage of the sebaceous gland (oil-secreting gland) in the skin. A true sebaceous cyst originating from the sebaceous gland is rare and is termed steatocystoma simplex or steatocystoma multiplex. Anyone can develop a sebaceous cyst, but this is rare in children before puberty.

A sebaceous cyst is a benign lump and appears as a smooth round swelling of variable size often with a characteristic ‘punctum’ in the centre. The sebaceous cyst is filled with ‘soft cheesy’ or ‘toothpaste’ like material which largely consists of keratin derived from skin. Sebaceous cysts can occur in any part of the body but are common on the scalp, ear, face, chest, back and scrotum. It is slow-growing and normally painless. A sebaceous cyst can get infected and may form an abscess requiring antibiotics and drainage. A sebaceous cyst can be multiple, especially on the scalp and in the scrotum. The diagnosis of sebaceous cyst can be made clinically and does not require any tests or investigations.

Sebaceous cysts are removed for cosmetic reasons, development of complication (infection, abscess), pain (rare) and hindrance in carrying out normal daily activities.

Excision of a sebaceous cyst is a day case procedure that can be performed under local anaesthetic. The cyst is usually removed in its entirety with the outer capsule. Occasionally the cyst will rupture during removal. Provided the cyst wall (capsule) is excised completely, this has no adverse consequences. The patients are able to go home after few hours and can normally return to work immediately. The skin is sutured using a dissolvable stitch that does not require removal. Occasionally skin glue is used to close small wounds after surgery. An infected sebaceous cyst requires a course of antibiotic followed by removal when the infection has subsided. An abscess will require drainage followed by excision at a later stage.

The wound is checked after a few weeks following the surgery. No further follow-up is normally required if the healing is satisfactory.