However, if they continue to grow, they may become unsightly, painful, and/or infected. Surgical
Surgical excision of a sebaceous cyst is a simple procedure to completely remove the sac and its contents, although it should be performed when inflammation is minimal. Three general approaches are used - traditional wide excision, minimal excision, and punch biopsy excision.The typical outpatient surgical procedure for cyst removal is to numb the area around the cyst with a local anaesthetic, then to use a scalpel to open the lesion with either a single cut down the center of the swelling, or an oval cut on both sides of the center point. If the cyst is small, it may be lanced, instead. The person performing the surgery will squeeze out the contents of the cyst, then use blunt-headed scissors or another instrument to hold the incision wide open while using fingers or forceps to try to remove the cyst wall intact. If the cyst wall can be removed in one piece, the "cure rate" is 100%. If, however, it is fragmented and cannot be entirely recovered, the operator may use curettage (scraping) to remove the remaining exposed fragments, then burn them with an electrocauterization tool, in an effort to destroy them in place. In such cases, the cyst may recur. In either case, the incision is then disinfected, and if necessary, the skin is stitched back together over it. A scar will most likely result. An infected cyst may require oral antibiotics or other treatment before or after excision.
If pus has already formed, then incision and drainage should be done along with avulsion of the cyst wall with proper antibiotics coverage. An approach involving incision, rather than excision, has also been proposed. References
External links

Overview at University of Maryland Medical Center
Epidermal Inclusion Cyst at eMedicine