Uterine polyps are growths attached to the inner wall of the uterus that expand into the uterus. Uterine polyps, also known as endometrial polyps, form as a result of cells in the lining of the uterus (endometrium) overgrowing. These polyps are usually noncancerous (benign), although some can be cancerous or can turn into cancer (precancerous polyps).

Uterine polyps range in size from a few millimeters — no larger than a sesame seed — to several centimeters — golf-ball-size or larger. They attach to the uterine wall by a large base or a thin stalk.

There can be one or many uterine polyps. They usually stay within the uterus, but they can slip through the opening of the uterus (cervix) into the vagina. Uterine polyps are most common in people who are going through or have completed menopause. But younger people can get them, too.

The following tests might be used to diagnose uterine polyps:

• Transvaginal ultrasound. A slender, wandlike device placed in the vagina emits sound waves and creates an image of the uterus, including its insides. A polyp might be clearly present or there might be an area of thickened endometrial tissue.

  A related procedure, known as hysterosonography (his-tur-o-suh-NOG-ruh-fee) — also called sonohysterography (son-oh-his-tur-OG-ruh-fee) — involves having salt water (saline) injected into the uterus through a small tube placed through the vagina and cervix. The saline expands the uterus, which gives a clearer view of the inside of the uterus during the ultrasound.

• Hysteroscopy. This involves inserting a thin, flexible, lighted telescope (hysteroscope) through the vagina and cervix into the uterus. Hysteroscopy allows for viewing the inside of the uterus.
• Endometrial biopsy. A suction catheter inside the uterus collects a specimen for lab testing. Uterine polyps might be confirmed by an endometrial biopsy, but the biopsy could also miss the polyp.

Most uterine polyps are benign. This means that they're not cancer. But, some precancerous changes of the uterus, called endometrial hyperplasia, or uterine cancers appear as uterine polyps. A tissue sample of the removed polyp is analyzed for signs of cancer.

The following tests might be used to diagnose uterine polyps:

• Transvaginal ultrasound. A slender, wandlike device placed in the vagina emits sound waves and creates an image of the uterus, including its insides. A polyp might be clearly present or there might be an area of thickened endometrial tissue.

  A related procedure, known as hysterosonography (his-tur-o-suh-NOG-ruh-fee) — also called sonohysterography (son-oh-his-tur-OG-ruh-fee) — involves having salt water (saline) injected into the uterus through a small tube placed through the vagina and cervix. The saline expands the uterus, which gives a clearer view of the inside of the uterus during the ultrasound.

• Hysteroscopy. This involves inserting a thin, flexible, lighted telescope (hysteroscope) through the vagina and cervix into the uterus. Hysteroscopy allows for viewing the inside of the uterus.
• Endometrial biopsy. A suction catheter inside the uterus collects a specimen for lab testing. Uterine polyps might be confirmed by an endometrial biopsy, but the biopsy could also miss the polyp.

Most uterine polyps are benign. This means that they're not cancer. But, some precancerous changes of the uterus, called endometrial hyperplasia, or uterine cancers appear as uterine polyps. A tissue sample of the removed polyp is analyzed for signs of cancer.

The following tests might be used to diagnose uterine polyps:

• Transvaginal ultrasound. A slender, wandlike device placed in the vagina emits sound waves and creates an image of the uterus, including its insides. A polyp might be clearly present or there might be an area of thickened endometrial tissue.

  A related procedure, known as hysterosonography (his-tur-o-suh-NOG-ruh-fee) — also called sonohysterography (son-oh-his-tur-OG-ruh-fee) — involves having salt water (saline) injected into the uterus through a small tube placed through the vagina and cervix. The saline expands the uterus, which gives a clearer view of the inside of the uterus during the ultrasound.

• Hysteroscopy. This involves inserting a thin, flexible, lighted telescope (hysteroscope) through the vagina and cervix into the uterus. Hysteroscopy allows for viewing the inside of the uterus.
• Endometrial biopsy. A suction catheter inside the uterus collects a specimen for lab testing. Uterine polyps might be confirmed by an endometrial biopsy, but the biopsy could also miss the polyp.

Most uterine polyps are benign. This means that they're not cancer. But, some precancerous changes of the uterus, called endometrial hyperplasia, or uterine cancers appear as uterine polyps. A tissue sample of the removed polyp is analyzed for signs of cancer.