In cases of visible cysts, such as those in the skin and wrists, your doctor will ask you when you first noticed the cyst, how quickly it grew, whether its size has changed, and if it is painful. During a physical exam, your doctor will look for redness and tenderness and will examine the size and shape of a suspected cyst. Often, this visual inspection is all that's needed.
Depending on the type of cyst, other tests may be necessary:
Knees — A Baker's cyst can almost always be diagnosed by looking at it. The cyst is not visible on standard X-rays, although X-rays can confirm the presence of osteoarthritis, which is associated with these cysts. Occasionally, an ultrasound is done if swelling extends into the back of the calf to be certain that the leg swelling is caused by the cyst and not a blood clot in the leg. Rarely, magnetic resonance imaging is necessary.
Ovaries — Ultrasound scans locate the cyst and tell if it is filled with fluid. Depending on the cyst's characteristics and a person's age, a repeat ultrasound may be done in a few months to see if the cyst goes away.
Breasts — A breast lump discovered by you or your doctor may be a cyst or solid tissue. Depending on your age, personal medical history and family medical history, your doctor may:
Repeat the breast examination after you have completed your next menstrual period.
Place a thin needle into the lump. If fluid can be drained, the lump is a cyst. Your doctor may send the fluid to a laboratory to be examined under a microscope.
Order a breast ultrasound that can determine if the lump is solid or fluid-filled.
Order a mammogram to look for any suspicious abnormalities before deciding if a biopsy is necessary. A biopsy is the removal of a tissue sample for laboratory testing.
Vagina — During a gynecological exam, your doctor will look for a tender lump, a Bartholin's gland cyst, near the opening of the vagina. Any redness, swelling, tenderness or pus suggests an infection.
Cervix — During a gynecological exam, your doctor may see fluid-filled Nabothian cysts on your cervix.
Kidneys — Ultrasound or computed tomography (CT) scans can detect kidney cysts.