Quality CareFind out why Mayo Clinic is the right place for your health care. Make an appointment.
Meet the StaffFind a directory of doctors and departments at all Mayo Clinic campuses. Visit now.
Research and Clinical TrialsSee how Mayo Clinic research and clinical trials advance the science of medicine and improve patient care. Explore now.
Visit Our SchoolsEducators at Mayo Clinic train tomorrow’s leaders to deliver compassionate, high-value, safe patient care. Choose a degree.
Professional ServicesExplore Mayo Clinic’s many resources and see jobs available for medical professionals. Get updates.
Give to Mayo ClinicHelp set a new world standard in care for people everywhere. Give now.
Mayo Clinic offers appointments in Arizona, Florida and Minnesota and at Mayo Clinic Health System locations.
Subscribe to Housecall
Our general interest e-newsletter keeps you up to date on a wide variety of health topics.
Tumors and cysts are two distinct entities.
Cyst. A cyst is a sac that may be filled with air, fluid or other material. A cyst can form in any part of the body, including bones, organs and soft tissues. Most cysts are noncancerous (benign). Although cancers can form cysts.
Some common examples of cysts include sebaceous (epidermoid) cysts — small bumps that form just beneath the skin — cysts that occur in the liver (hepatic), cysts that occur in the kidneys (renal), and breast and ovarian cysts. It's important to note, however, that nearly all cancers are capable of producing cysts.
Cysts that appear uniform after examination by ultrasound or a computerized tomography (CT) scan are almost always benign and should simply be observed. If the cyst has solid components, it may be benign or malignant and should have further evaluation. The best test to determine whether a cyst or tumor is benign or malignant is to take a sample of the affected tissue — or, in some cases, the entire suspicious area — by removing it and studying it under a microscope. This is known as a biopsy.
Timothy J. Moynihan, M.D.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic.
Mayo Clinic is a not-for-profit organization and proceeds from Web advertising help support our mission. Mayo Clinic does not endorse any of the third party products and services advertised.
A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.