Ultrasounds Aren't Typically Used to Detect Cervical Cancer: Learn Why

An ultrasound isn’t the best way to screen for or diagnose cervical cancer. An ultrasound is an imaging test that uses sound waves to look at what’s happening inside the body. It’s often used in obstetrics and gynecology to monitor fetal development during pregnancy and to identify fibroids, cysts, and other growths.

While signs of certain types of cervical cancer can be detected by certain types of ultrasound tests, healthcare professionals are unlikely to spot cervical cancer during an unrelated exam. Your ultrasound technician may not be trained to identify cervical cancer, especially if you’re undergoing this imaging test for another purpose.

There are more reliable ways to screen for and diagnose cervical cancer, including:

• Pap smear test
• HPV test
• colposcopy
• biopsy

However, an ultrasound may be used later on in the cervical cancer diagnosis process. After a cervical cancer diagnosis is confirmed with a biopsy, a doctor may recommend several imaging tests to see if the cancer has spread to nearby tissues or other parts of the body.

Cervical cancer screening typically includes a Pap test, an HPV test, or both.

Regular screenings with such tests are important in detecting this type of cancer in its early, treatable stages. It’s estimated that about half of all cervical cancer cases occur in people who have never undergone either Pap or HPV testing.

Pap tests for cervical cancer

A Pap test looks for the presence of abnormal cells on the cervix. It’s usually conducted during a regularly scheduled gynecological exam. A healthcare professional inserts a speculum into the vagina and then uses a swab to take a sample of cells. This sample is sent to a lab for analysis.

If your Pap test results are “abnormal,” a doctor may recommend further testing to confirm or rule out cervical cancer. They may also want to monitor you more closely, with regularly scheduled exams.

HPV test for cervical cancer

The most common cause of cervical cancer is HPV. Also conducted during a pelvic exam, HPV testing is done to look for the presence of this virus. The benefit of this screening is that doctors can detect HPV before it causes precancerous changes to cervical cells.

HPV is extremely common and most cases don’t lead to cancer. There are more than 100 strains of HPV, some of which are associated with a higher risk of cervical cancer.

HPV testing may be especially beneficial if you haven’t had an HPV vaccine or if you’ve yet to complete the recommended vaccination schedule. But all people with a cervix should get regular Pap tests, as the current vaccine doesn’t protect against all strains of HPV.

Colposcopy

Pap and HPV tests help screen for cervical cancer. When the results of these tests are abnormal, healthcare professionals typically recommend additional testing. The first step is usually a colposcopy. This exam involves the use of a magnifying tool called a colposcope, which allows a doctor to see the surface of your cervix in detail.

For you, this exam won’t be much different from a typical pelvic exam. A doctor will insert a speculum into your vagina, then look through a colposcope to see your cervix. They may add an acidic substance to the cervix to help highlight abnormal cells, but this shouldn’t cause any additional discomfort.

If the results of your colposcopy are abnormal, a doctor will recommend a biopsy, which involves taking a small sample of tissue and sending it off to a lab for further analysis. This may be done at the same time as your colposcopy, or at a later date.

Different types of biopsies used to diagnose cervical cancer include:

• Colposcopic biopsy: This biopsy is done during a colposcopy. A doctor identifies an abnormal area of the cervix and then removes a small piece of tissue from that area.
• Cone biopsy (conization): This method involves the removal of a cone-shaped section of cervical tissue. It’s also used as a treatment to remove early stage cervical cancer.
• Endocervical scraping (endocervical curettage): Often done as a follow-up to other biopsies that have inconclusive results, this method involves the removal of tissues within the endocervical canal.

If the results of your biopsy are positive for cancer, doctors may order additional tests to help them determine how far the cancer has spread. These may include:

• a pelvic exam
• a rectal exam
• cystoscopy, which examines the inside of the bladder and urethra
• colonoscopy, which examines your colon

If a doctor suspects that cervical cancer has spread, they may order imaging tests to confirm their findings and inform their treatment approach. These images can also help a doctor determine what stage of cervical cancer you have.

Imaging tests may include:

• Chest X-rays to determine whether the cancer has spread to your lungs.
• Intravenous (IV) urography, which is a type of X-ray that examines the urinary system, including your kidneys.
• Computed tomography (CT) scans of the pelvis or other areas of the body to measure a tumor’s size and look for the spread of cancer.
• A CT scan combined with a positron emission tomography (PET) scan to capture more detailed images.
• Magnetic resonance imaging (MRI), which may be more effective than a CT scan at taking images of soft tissues.

There are several different types of ultrasound tests. They’re used in different ways to capture images of what’s happening inside various parts of the body.

Abdominal ultrasound

An abdominal ultrasound is used to take images of abdominal organs, such as your liver, spleen, and pancreas. It may also take pictures of blood flow within such organs. A doctor may order an abdominal ultrasound to assess any of the following issues:

• blood clots
• fluid or pus accumulation
• infections
• obstructions
• cysts or tumors
• fetal development during pregnancy

However, an abdominal ultrasound isn’t used to detail images of the cervix or the pelvic area more generally.

Pelvic and transvaginal ultrasound

As the name suggests, a pelvic ultrasound details images of tissues, structures, and organs around the pelvis. These may include the cervix, uterus, fallopian tubes, and vagina.

A pelvic ultrasound is performed on the outside of the body, while a transvaginal ultrasound uses an imaging wand that’s placed inside the vagina.

While a pelvic ultrasound may detect fibroid tumors and other growths around your pelvis, this method isn’t the preferred way to diagnose cervical cancer.

A doctor may also order a transabdominal or transvaginal pelvic ultrasound to examine:

• potential structural abnormalities
• possible pelvic inflammation or related infections
• fetal development during pregnancy
• a possible ectopic pregnancy
• potential fetal conditions
• blood flow in organs
• the overall thickness and length of the cervix

Screening for cervical cancer is the best way to find cancer early, before it spreads. According to the American Cancer Society, the 5-year relative survival rate for localized, or early stage, cervical cancer is 92%.

As such, the Centers for Disease Control and Prevention (CDC) offers the following recommendations for cervical cancer screening:

Keep in mind, you should tell a doctor about any unusual changes between screenings. Talk with a doctor if you’re experiencing any of the following symptoms:

• abnormal spotting or bleeding
• heavy menstrual periods
• unusual vaginal discharge
• pelvic pain
• bleeding or discomfort after sex

While you might need an ultrasound for another medical reason, such as during pregnancy, this isn’t a replacement for regular cervical cancer screening. It’s important to get these tests on a regular schedule to help identify problems before they progress.

If a doctor does find unusual cell changes after a Pap test, or you have a positive HPV test result, they’ll advise you about follow-up testing. But you should talk with a doctor if you’re experiencing any abnormal symptoms. The earlier this cancer is detected, the better the outcome.