A cyst is a small sac that can grow on the skin, organs, and other body tissues. There are hundreds of different types of cysts, most of which are harmless. In some rare cases, however, these structures can be a sign of a more serious condition, such as a hormonal imbalance or cancer.
What a sac is filled with determines whether it is a cyst, an abscess, or a tumor. Cysts are usually filled with fluid, such as skin oil, although they may also contain air, water, or semi-solid matter from the body. Abscesses are often the result of an infection and contain pus. Tumors are typically filled with body tissue.
Small lumps on the skin often develop when oil or other fluids cannot flow freely from the body. Many harmless cysts on the skin occur when hair follicles become damaged or blocked. Oil-secreting glands known as sebaceous glands can also rupture and become blocked, stopping the oil from shedding normally. Most lumps caused by blocked glands or follicles are benign, meaning that they are generally harmless and not a sign of a more serious problem, like cancer.
Hormonal imbalances can sometimes cause the growth of sacs on internal organs. Breast and ovarian cysts are often linked to an imbalance in estrogen, which can interrupt ovulation cycles and cause tissue overgrowth. These conditions can sometimes be treated with hormone therapy.
Some medical professionals believe that chronic inflammation or trauma can also cause some types of cysts to grow on body tissue. While the exact role these factors play is unclear, some experts suggest that injuries may cause the depletion of the membranes that cover joints and organs, allowing cysts to form more easily. Infections in the body may also have a similar effect, causing a breakdown of tissue that leads to fluid-filled sacs.
In some cases, a cyst may form while a baby develops in the womb. This can sometimes signify organ disorders, since they tend to appear on organs that are not developing correctly. Similarly, genetic conditions such as Gardner's Syndrome, in which polyps, tumors, and cysts form throughout the body, or inherited genetic mutations may raise a person's risk of developing these growths.
Occasionally, cysts can be related to tumors. They may appear on top of developing growths, or form on the same organs. While tumors can be cancerous, many varieties are actually harmless.
When cysts develop on the skin, the most common symptom is a small lump or bump. These growths are generally small and match the color of the skin, though some may seem irritated and red. They may come and go on their own, or persist for weeks. Many skin cysts are painless and do not cause other symptoms; one that grows on a joint, such as behind the knee, however, may cause pain or irritation.
Breast-tissue cysts are often somewhat painful. Instead of developing on the surface, they tend to be deeper inside the tissue, and may be found by doing a manual examination on the breasts. Any painful or painless lumps in the breast should be checked out by a medical professional.
Growths on organs may be somewhat more difficult to identify. They are often associated with pain or decreased function of the organ; for example, people who suddenly have trouble urinating may have developed a growth on the kidney or bladder. In most cases, however, organ cysts have no visible symptoms and are only found through body-tissue scans, such as ultrasounds or MRIs.
Types of Cyst
Skin growths include several different categories. Pilar cysts tend to form on the scalp, and are caused by blocked hair follicles. Baker's cysts appear behind the knee joint, and can be very swollen or painful. Spermatoceles grow on the skin surrounding the testicles, and are generally harmless and painless.
Common organ growths include those on the liver, kidney, and pancreas. These may decrease the function of the organs if they grow large, but they are often harmless and cause no symptoms. Ovarian cysts are fairly common in women of childbearing age. Occasionally, they can be extremely large and painful, and may lead to a condition known as polycystic ovary syndrome, in which the surface of the ovaries is rippled with many lumps due to hormonal imbalances.
Sacs can also grow in the mouth and throat. Children may develop dentigerious sacs, which are tender fluid-filled growths that appear around teeth just before they break through the gums. Vocal fold nodules form in the throat and on the vocal chords, causing hoarseness and changes in the voice.
Diagnosis and Treatment
Medical professionals will often diagnose skin growths simply by looking at the lumps directly. Some health care providers may do a needle biopsy to take a sample of the material in the cyst. This type of biopsy is typically used to determine whether the growth is benign or cancerous.
Imaging scans, such as ultrasounds and MRIs, are often used to examine internal growths. These scans can help identify whether there are cysts, where they are located, and how large they are. Depending on the results of the scan, a doctor may then recommend a needle biopsy or removal if the growth seems suspicious.
After diagnosing the growth, treatment options vary. Some sacs are harmless and small, and may simply be left alone. If a cyst is painful or growing, a medical professional may suggest draining the fluid out. Large growths may be surgically removed. For growths caused by hormones, such as breast and ovarian cysts, treatment may focus on correcting the imbalance to prevent further problems.