Sebaceous CystSebaceous Cyst

A sebaceous cyst, more accurately called an epidermal inclusion cyst or epidermoid cyst, is a sac beneath the skin filled with keratin and dead skin cells rather than sebum. It forms when these cells become trapped below the surface and accumulate inside a capsule, creating a firm, round, skin-colored lump that usually grows slowly and remains painless unless it becomes inflamed or infected. The cyst contains thick material often described as cheese-like. Two factors determine how well removal goes. The entire capsule wall must come out with the contents because any remaining fragment can produce keratin and regenerate the cyst. Timing also matters: excising an actively inflamed cyst raises the risk of recurrence, so the inflammation is treated first and removal is scheduled a minimum of eight weeks after it resolves. Dr. Julia Tzu performs the excision at her Financial District office and closes the site with attention to the resulting scar, particularly on the face and neck, where the scar is often the reason a patient sought treatment.

4 min read · Last updated: 2026-02-08 · Reviewed by Dr. Julia Tzu , MD, FAAD, FACMS

• Epidermal inclusion cysts form when keratin and dead skin cells become trapped beneath the skin [1]
• Complete removal of the cyst wall (capsule) prevents recurrence [2]
• Cysts that are only drained often recur because the sac can refill [2]
• Never attempt to pop or drain a cyst at home, as this can cause infection [1]

• Small, round, movable bump under the skin
• Slow-growing lump
• Skin-colored, whitish, or yellowish appearance
• Small central opening (punctum) sometimes visible
• Thick, cheese-like or cottage cheese-like material inside
• Usually painless unless infected
• May have unpleasant odor if punctured or infected
• Redness, tenderness, and swelling if infected

• Redness, pain, swelling or warmth around the cyst, which are signs of inflammation or infection and are treated before any excision
• A cyst that ruptured, or one currently draining
• Growth or a change in size or texture
• A cyst positioned where it catches, rubs, or interferes with daily activity
• Cosmetic concern, particularly on the face, neck, or scalp
• Uncertainty about what the lump is, as several other growths present the same way
• A cyst returning after a previous removal, which suggests capsule was left behind
• An inflamed cyst now settled down, because removal is planned at least eight weeks afterwards

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• Keratin and dead skin cells trapped under skin
• Blocked or damaged hair follicle
• Skin trauma or injury
• Acne or other skin conditions
• Ruptured sebaceous gland
• Developmental defect in skin
• Genetic predisposition

We offer a service to help manage this condition: Cosmetic Cyst Removal Surgery .

• Benign with excellent prognosis
• Complete removal including capsule prevents recurrence
• Drainage alone often leads to recurrence
• Some cysts remain stable for years without treatment
• Infection can occur but is treatable
• No risk of transformation to cancer

Triple board-certified cosmetic and surgical dermatologist · Manhattan's Financial District

Trained at Stanford, Johns Hopkins, Penn & NYU

✓ Complete sac removal to limit recurrence

When Dr. Julia Tzu surgically removes a sebaceous cyst, she carefully dissects out the entire sac, not just its contents, since leaving the sac wall behind is what allows a cyst to recur. She then closes the site with cosmetically optimized technique to minimize the appearance of the scar.

More About Dr. Tzu →

1. What are the symptoms of Sebaceous Cyst?
2. When should you seek care for Sebaceous Cyst?
3. What causes Sebaceous Cyst?
4. How is Sebaceous Cyst treated?
5. Prognosis
6. FAQs
7. Sources

This article draws from 3 peer-reviewed sources.

• [1] Cleveland Clinic – Epidermal Inclusion Cysts (Sebaceous Cysts)
• [2] Cleveland Clinic – Cyst Removal
• [3] Mayo Clinic – Epidermoid Cysts

Medically reviewed by Dr. Julia Tzu , MD, FAAD, FACMS · Last reviewed: 2026-08-31