Menu Healthy Lifestyle Diseases & Conditions First Aid Symptoms Tests & Procedures Videos Definitions FAQs Epidermoid cystUpdated: 2020-04-07OverviewAn epidermoid cyst is a noncancerous small bump beneath the skin. This type of cyst is common on the face, neck, and trunk.SymptomsA tiny blackhead may plug the central opening. Sometimes, a thick, yellow, foul-smelling liquid drains from it. The area around it may be red and swollen.TreatmentsA troublesome cyst can be removed. © 1998-2022 Mayo Foundation for Medical Education and Research(MFMER). All rights reserved. Terms of Use