Sebaceous cyst is a globular swelling seen in the skin; exuding thick, whitish, pasty and foul smelling material; which may come out itself or on squeezing the swelling. Many times a bluish mouth is seen over it called punctum.
Sebaceous cyst is a cyst of oil secreting glands in the skin, whose mouth is blocked. The oily secretions, sebum being unable to come out accumulates and the swelling gradually grows in size over months. Sometimes it grows to very large in size. Many times a bacterium called Domodex Folliculorum can be isolated from the sebum.
It can be seen almost on every part of body; but commonly seen over scalp, back, chest wall and scrotum. Sometimes the thick material comes out gradually and hardens to give rise to a throne like projection called sebaceous horn. Sometimes the scalp sebaceous cysts are so infected, ulcerated and large that those confuse with infected skin tumour.
Sometimes it gets infected and inflammation spreads to the surrounding area of skin. That may give rise to fever and pain in otherwise painless swelling
Uncomplicated sebaceous cyst can be diagnosed very comfortably from the shape of the swelling, adherence to the skin, some fluctuation of the content and presence of punctum.
Sebaceous cyst can nicely be removed along with its wall called cyst wall, under local anaesthesia. The tricky aspect of the removal is not to leave any fragment of cyst wall inside the wound.
In case of inflammation, it becomes difficult to remove the cyst in Toto. Here as a first step the pus and the infected sebum is drained. If possible, attempt is made to remove the cyst wall, if not total, as much as possible. The wound is left open. Dressing is advised daily and attempt is made to remove the remaining portion of cyst wall. After the wound becomes healthy, without any trace of cyst wall, secondary closure is advised.
Alternatively, after the drainage of pus and sebum, the wound is allowed to heal; when the wound shrinks in size and inflammation subsides; surgery is undertaken to completely remove the cyst wall.
That possibly will prevent recurrence of the cyst.