Tumors and cysts are unusual growths that may develop either inside or on the outside of the body. Although they may share certain characteristics, tumors and cysts differ from one another in several important ways.
“A tumor is a growth made up of abnormal cells and often contains a combination of solid tissue and, in some cases, fluid. Most tumors have at least some solid component. A cyst, by contrast, is a fluid filled sac,” explains Joshua G. Cohen, M.D., F.A.C.O.G., F.A.C.S., medical director of the Gynecologic Cancer Program at City of Hope® Orange County Lennar Foundation Cancer Center.
Determining whether a growth in the body is a tumor or a cyst usually requires a physical exam by a doctor and, often, an imaging test. This article covers the basics on cysts and tumors, including:
- What is a cyst?
- Can cysts be cancerous?
- What is a tumor?
- Are all tumors cancerous?
- Cyst versus tumor
- Cancerous cyst versus normal cyst
If you or a loved one has been diagnosed with cancer and are looking for a second opinion, call us 24/7 at 877-460-4673.
What Is a Cyst?
A cyst is a small sac of tissue. Although cysts are usually filled with fluid or pus, they may also contain air or other substances.
“Some cysts are simple —essentially a water filled pocket — while others contain multiple fluid-filled compartments, like the chambers of a honeycomb,” says Dr. Cohen.
Cysts may appear anywhere on the body and be caused by a range of health issues, including:
- Blocked glands or ducts in the skin
- Long-term inflammation
- Certain parasites, like tapeworms and roundworms
- Some kinds of genetically inherited conditions
In some cases, there may be no clear reason why a patient develops a cyst.
Can Cysts Be Cancerous?
“Cysts can be either benign or cancerous,” says Dr. Cohen.
He adds: “It’s important to talk with your health care provider about the characteristics of any mass: Where is it located? How long has it been there? What features were seen on imaging?”
After considering these factors, a patient’s doctor or care team may recommend several approaches, including further tests, “watchful waiting” (which means monitoring the cyst closely) or removing the cyst.
What Is a Tumor?
A tumor is an abnormal mass of tissue caused when the cells in the body start to behave unusually and grow out of control. Tumors may occur anywhere in or on the body and may be caused by one or multiple factors, including:
- Changes to the body on a genetic level
- Exposure to too much ultraviolet light
- Excessive use of alcohol
- Use of tobacco
- Exposure to radiation or certain environmental toxins
- Viruses or infections
Are All Tumors Cancerous?
“Just as cysts can be benign or malignant, tumors can also be either benign or cancerous,” Dr. Cohen says. Patients who are concerned about a new or growing mass should make an appointment to see their primary doctor for further testing or evaluation.
Cyst Versus Tumor
Cysts and tumors may look or feel similar, but there are several key differences between these two types of masses, as detailed below.
A tumor: This is made up of solid tissue that has grown abnormally and formed a lump, swelling or mass. Because it is made of tissue, it tends to be harder to the touch.
A cyst: This is more often made up of fluid, air or softer tissue and tends to be softer or more pliable.
One other important difference is that the majority of cysts are benign (noncancerous), while tumors may be either benign or malignant (cancerous).
“The most important question for patients with a suspected cyst is whether it is causing symptoms such as pain, pressure or discomfort,” says Dr. Cohen. “If symptoms are present, further work up is typically warranted regardless of how benign the cyst appears.”
Cancerous Cyst Versus Normal Cyst
There is no way to know whether a cyst is cancerous (malignant) or noncancerous (benign) simply based on how it looks or feels. That’s why Dr. Cohen recommends that any patient who notices a new growth in his or her body — or an existing mass that is growing or changing — make an appointment as soon as possible with a primary care doctor.
“Most growths are benign, but a small subset can be dangerous. Early evaluation prompted by patients advocating for themselves can make a meaningful difference,” he says.
During a doctor’s visit, patients should ask their medical team about their next steps, including:
- Whether they should undergo blood tests
- If additional imaging is recommended
- Whether the cyst should be removed via surgery
- When repeat imaging should be done, if their recommendation is “watchful waiting”
Dr. Cohen’s key piece of advice?
“Know your body, pay attention to changes and seek care if something feels different or concerning,” he says.
If you or a loved one has been diagnosed with cancer and are looking for a second opinion, call us 24/7 at 877-460-4673.