Cyst
A cyst is a closed pocket or pouch of tissue. It can be filled with air, fluid, pus, or other material.
Considerations
Cysts may form within any tissue in the body. Cysts within the lung generally are air-filled, while cysts involving the lymph system or kidneys are fluid-filled. Certain parasites, such as trichinosis, dog tapeworm (Toxocara canis), and echinococcus, can form cysts within the muscles, liver, brain, lungs, and eyes.
Cysts are common on the skin. They develop as a result of infection, clogging of sebaceous glands (acne-related cysts), or around a foreign object stuck in the skin.
See also: Pilonidal dimple
References
Habif TM. Principles of diagnosis and anatomy. In: Habif TP, ed. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 1.
Updated: 4/28/2012
Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Read More
Notice: The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2012, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.