Gestational Trophoblastic Disease: Diagnosis

Approved by the Cancer.Net Editorial Board, 11/2022

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to find, or diagnose, a tumor. They also do tests to learn if it is cancerous and, if so, if it has spread to another part of the body from where it started. If the cancer has spread, it is called metastasis. Doctors may also do tests to learn which treatments could work best.

For most types of tumors, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.

How gestational trophoblastic disease (GTD) is diagnosed

There are different tests used for diagnosing GTD. Not all tests described here will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of disease suspected

  • Your signs and symptoms

  • Your age and general health

  • The results of earlier medical tests

In addition to a physical examination, the following tests may be used to diagnose GTD:

  • Pelvic examination. The doctor may feel the uterus, vagina, ovaries, bladder, and rectum to check for lumps or any unusual changes. This is similar to the physical exam done during an annual gynecologic checkup.

  • Human chorionic gonadotropin (hCG) test. Tumor markers are substances found at higher-than-normal levels in the blood, urine, or body tissues of people with a tumor. Pregnancy normally causes high levels of hCG in the blood and urine. High levels of hCG in a person who is not pregnant could mean that GTD is present. hCG tests are also helpful tests to monitor a patient's recovery during and after treatment for GTD.

  • Other lab tests. Additional blood and urine tests may be done, including tests to check the thyroid, liver, kidney, and bone marrow function.

  • Ultrasound. Also called a sonogram, an ultrasound creates a picture of the internal organs using sound waves. In a transvaginal ultrasound, an ultrasound wand is inserted into the vagina and aimed at the uterus to take the pictures.

  • X-ray. An x-ray creates a picture of the structures inside of the body using a small amount of radiation. A chest x-ray may be done to see if the tumor has spread outside of the uterus.

  • Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye is injected into a patient’s vein or given as a drink or pill to swallow.

  • Magnetic resonance imaging (MRI). An MRI produces detailed images of the inside of the body using magnetic fields, not x-rays. MRI can be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow. In GTD, MRIs are most often used to take pictures of a patient’s brain.

After diagnostic tests are done, your doctor will review the results with you. If the diagnosis is GTD, these results also help the doctor describe the disease in more detail. This is called staging.

The next section in this guide is Stage and Risk Grouping. It explains the system doctors use to describe the extent of the disease. Use the menu to choose a different section to read in this guide.