What should you know about a dermoid cyst in the scalp?

The scalp commonly develops pilar, also called trichilemmal, cysts from structures associated with hair follicles. A rounded lump may feel smooth or firm and can move slightly under the skin. It may be painless while small, then become tender if irritated or inflamed. The wording dermoid cyst is sometimes used broadly for a developmental cyst, but a clinician needs to examine the lump to identify its type and depth. A scalp lump is not diagnosed safely from appearance alone.

Book an assessment if the lump is new, growing, recurrent, or difficult to see beneath the hair. Note when it appeared, whether it moves, and whether there has been pain, redness, or discharge. Do not squeeze, pierce, or cut it, because this can injure the skin and introduce infection. If removal is appropriate, [Cyst Removal](/treatments/surgical-dermatology/cyst-removal/) usually involves taking out the cyst and its surrounding capsule when feasible. You can also read about [Skin Lumps](/symptoms/skin-lumps/) while arranging an examination.

Arrange prompt medical care for rapid enlargement, increasing warmth, marked tenderness, spreading redness, pus, fever, or a wound that does not settle. Seek urgent help for severe headache, repeated vomiting, confusion, weakness, or a lump associated with a recent significant injury. These features do not identify the cause by themselves, but they need timely assessment.

Does the lump feel like a pilar cyst, a dermoid cyst, or another type of skin lump? Is imaging needed because of its depth or position? Can it be observed, or would removal reduce recurrence or irritation? What wound care would follow the procedure?