On ultrasound, a simple cyst looks like a smooth, round, black (anechoic) sac with a thin, distinct wall and often shows a brighter area behind it (posterior enhancement), indicating it's fluid-filled. Complex cysts, however, can have thicker walls, internal divisions (septations), or bright spots (echogenic material) from blood or tissue, appearing less uniform and sometimes requiring further investigation.
A cyst is a fluid-filled sac with thin walls, while a tumor is a solid mass of tissue cells. Medical imaging provides the only reliable way to distinguish between them—ultrasound shows cysts as dark, fluid-filled areas, while tumors appear as solid masses that enhance with contrast on CT or MRI scans.
Even noncancerous brain cysts can cause problems by pressing against brain tissue causing headaches, vision problems or nausea.
Symptoms of an ovarian cyst
The 1-2-3 rule is a simple aide-mémoire describing the nomenclature of any small simple anechoic cystic appearing structure within an ovary on ultrasound: <1 cm = follicle. 1-2 cm = dominant follicle. >3 cm = cyst.
Many ovarian cysts are painless and go unnoticed. However, some may cause pelvic or lower abdominal discomfort, especially if they grow large or occur around the time of ovulation. The pain may be dull and intermittent, or more noticeable during menstruation or intercourse.
Some cysts are cancerous and early treatment is vital. If left untreated, benign cysts can cause serious complications including: Infection – the cyst fills with bacteria and pus, and becomes an abscess. If the abscess bursts inside the body, there is a risk of blood poisoning (septicaemia).
Large brain cysts can block the normal flow of cerebrospinal fluid, which can cause increased pressure on the brain. Cysts can also leak into other areas of the brain, or blood vessels on the cyst's surface can bleed into the cyst causing a hematoma. If left untreated, cysts can cause neurological damage.
It's useful in some situations because it can usually be done quickly and doesn't expose people to radiation. Ultrasound images are not as detailed as those from CT or MRI scans. Ultrasound cannot tell whether a tumor is cancer.
"A radiologist can tell the difference between a cyst and a tumor using a breast ultrasound," says Dr. Terrell. "A cyst will have smooth walls and be filled with clear fluid, whereas a tumor will look solid." A small, simple breast cyst typically doesn't need treatment and should go away on its own over time.
Black in an ultrasound image represents liquid, like amniotic fluid or a fluid-filled cyst. Most sound waves pass through fluid-filled areas, with only a small amount reflected back, making the area appear like a black spot on ultrasound results.
In most cases, the answer is no. Simple cysts are almost always benign, and complex or complicated cysts are usually benign as well — but not always. “In rare cases, a complex or complicated cyst can harbor malignant cells,” says Dr. Racz.
Cancer appears hypoechoic on a sonogram, presenting as a dark grey patch surrounded by light grey or white healthy tissues. It may also have an irregular shape with angular or asymmetrical edges. Not all hypoechoic mass (tumours) are cancerous, so you shouldn't feel anxious because of the colors on your sonogram.
Blood tests might be ordered to look for markers of disease, infection, or other conditions that might explain the abnormal imaging results. Depending on the area of concern, you might need a more detailed imaging test, such as an MRI or CT scan, which can provide more information than a standard ultrasound.
Most cysts are benign (non-cancerous), but some are cancerous or precancerous and must be removed. In addition, if a cyst is filled with pus, that means it's infected and could form an abscess, so you should see a doctor if you feel pain when you touch a cyst.
von Hippel-Lindau syndrome. A rare, inherited disorder that causes tumors and cysts to grow in certain parts of the body, including the brain, spinal cord, eyes, inner ear, adrenal glands, pancreas, kidney, and reproductive tract. The tumors are usually benign (not cancer), but some may be malignant (cancer).
Some cysts decrease in size, while others continue to grow until you get treatment. Without treatment, you may have the cyst for the rest of your life.
Pilonidal cysts usually occur when hair punctures the skin and then becomes embedded. If a pilonidal cyst becomes infected, it can be very painful. The cyst can be drained through a small cut in the skin. Sometimes, surgery is needed.
Symptoms of a skin cyst
You may be given IV (intravenous) pain medicines through a needle inserted into your vein. You may need to have fluids or blood replaced due to internal bleeding. In rare cases, a ruptured ovarian cyst may need surgery. This may be an emergency surgery.
Early Warning Signs of Ovarian Cysts
Medium-sized cysts (2-4 inches): These may need ongoing monitoring, especially if they are causing symptoms. Large cysts (over 4 inches): These can cause serious problems, such as: Ovarian torsion, which can damage the ovary and is a medical emergency. Pressure on nearby organs, like the bladder or bowel.
Hailey Bieber recently opened up about having ovarian cysts — including one "the size of an apple.” Is this normal? We asked Dr. Brooke Chalk to talk us through what's common and what's worth a visit to your doctor.