How Is Uterine Sarcoma Diagnosed?
Some uterine sarcomas are diagnosed during or after surgery for what is thought to be benign fibroid tumors. Most, though, are diagnosed because of symptoms.
If you have symptoms of uterine cancer, the first step is to see your doctor. He or she will examine you and may order some tests.
Consultation, medical history, and physical exam
Your doctor will ask you about your personal and family medical history. You also will be asked about any symptoms, risk factors, and other health problems. You will be given a general physical and a pelvic exam. If your doctor suspects cancer, you may be referred to a gynecologist or a doctor specializing in cancers of the female reproductive system (gynecologic oncologist).
Sampling and testing endometrial tissue
To find the cause of abnormal uterine bleeding, a sample of tissue will be removed from the lining of the uterus and looked at under a microscope. The tissue can be removed by endometrial biopsy or by dilation and curettage (D&C). Often a hysteroscopy is done with the D&C (see below).
These procedures let the doctor see if the bleeding is caused by benign endometrial overgrowth (hyperplasia), endometrial carcinoma, uterine sarcoma, or some other disease. The tests will find many endometrial stromal sarcomas and undifferentiated sarcomas, but less than half of leiomyosarcomas (abbreviated LMSs). These tests don't find all LMSs because these cancers begin in the muscle layer of the wall of the uterus. To be found by an endometrial biopsy or D&C, they need to have spread from the middle (muscle) layer to the inner lining of the uterus. Often it is only possible to diagnose a LMS by removing it (with surgery).
In this procedure, a very thin, flexible tube is inserted into the uterus through the cervix. Then, using suction, a small amount of the uterine lining (endometrium) is removed through the tube. Suctioning takes about a minute or less. The discomfort is similar to severe menstrual cramps and can be helped by taking a nonsteroidal anti-inflammatory drug such as ibuprofen an hour before starting. This procedure is usually done in the doctor's office.
This is a procedure that allows doctors to look inside the uterus. A tiny telescope is inserted into the uterus through the cervix. To get a better view, the uterus is then expanded by filling it with salt water (saline). This lets the doctor see and biopsy anything abnormal, such as a cancer or a polyp. This procedure is usually done with the patient awake, using local anesthesia (numbing medicine). But if a polyp or mass has to be removed, general or regional anesthesia is sometimes used (with general anesthesia, drugs are given that put you into a deep sleep and keep you from feeling pain; regional anesthesia is a nerve block that numbs a larger area of the body).
Dilation and curettage
If the results of the endometrial biopsy are not conclusive (meaning they can't tell for sure if cancer is present), a procedure called dilation and curettage (D&C) must be done. A D&C is usually done in the outpatient surgery area of a clinic or hospital. This procedure is done while the woman is under general or regional anesthesia or conscious sedation (medicine is given into a vein to make her drowsy) and takes about an hour. In a D&C, the cervix is dilated and a special surgical instrument is used to scrape the endometrial tissue from inside the uterus. A hysteroscopy may be done as well. Most women have little discomfort after this procedure.
Testing endometrial tissue
Any tissue samples obtained by these procedures are looked at under a microscope to see if cancer is present. If cancer is found, the lab report will say if it is a carcinoma or sarcoma, what type it is, and its grade.
A tumor's grade is based on how much it looks like normal tissue under the microscope. If the tumor looks a lot like normal tissue, it is called low grade. If it doesn't at all look like normal tissue, it is high grade. The rate at which the cancer cells appear to be growing is another important factor in grading a uterine sarcoma. High-grade sarcomas tend to grow and spread more quickly than low-grade sarcomas.
The tissue may also be tested to see if the cancer cells have estrogen receptors and progesterone receptors. These hormone receptors are found on many endometrial stromal sarcomas. Cancers with estrogen receptors on the cells are more likely to grow in response to estrogen, while those with progesterone receptors often have their growth decreased by progesterone. These cancers may stop growing (or even shrink) when treated with certain hormone drugs. Checking for these receptors helps predict which patients will benefit from treatment with these drugs.
Cystoscopy and proctoscopy
If a woman has signs or symptoms that suggest uterine sarcoma has spread to the bladder or rectum, the inside of these organs can be looked at through a lighted tube. These examinations are called cystoscopy and proctoscopy, respectively. They are rarely done in the diagnosis and work-up of patients with uterine sarcoma.
Ultrasound tests use sound waves to take pictures of parts of the body. For a transvaginal ultrasound, a probe that gives off sound waves is inserted into the vagina. The sound waves are used to create images of the uterus and other pelvic organs. These images can often show any tumor that is present and whether or not it affects the myometrium (muscular layer of the uterus).
For an ultrahysterosonogram or saline infusion sonogram, salt water (saline) is placed into the uterus through a small tube before the transvaginal sonogram. This allows the doctor to see abnormalities of the uterine lining more clearly.
The CT scan is an x-ray test that produces detailed cross-sectional images of your body. Instead of taking one picture, like a standard x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body.
A CT scanner has been described as a large donut, with a narrow table in the middle opening. You will need to lie still on the table while the scan is being done. CT scans take longer than regular x-rays, and you might feel a bit confined by the ring while the pictures are being taken.
Before the test, you may be asked to drink 1 to 2 pints of a liquid called oral contrast. This helps outline the intestine so that certain areas are not mistaken for tumors. You may also receive an IV line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline structures such as blood vessels in your body.
The injection can cause some flushing (redness and warm feeling). A few people are allergic to the dye and get hives or, rarely, have more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have any allergies or have ever had a reaction to any contrast material used for x-rays.
CT scans are rarely used to diagnose uterine cancer, but they may be helpful in seeing if the cancer has spread to other organs.
CT-guided needle biopsy: CT scans can also be used to guide a biopsy needle precisely into a suspected tumor. For this procedure, the patient remains on the CT scanning table while the doctor advances a biopsy needle through the skin and toward the tumor. CT scans are repeated until the needle is within the mass. A fine needle biopsy sample or a larger core needle biopsy sample is then removed to be looked at under a microscope. This isn’t used to biopsy tumors of the uterus, but can be used to biopsy suspected areas of metastasis.
Magnetic resonance imaging
Magnetic resonance imaging (MRI) scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of the body. Not only does this produce cross-sectional slices of the body like a CT scanner, it can also produce slices that are parallel with the length of your body. A contrast material might be injected just as with CT scans but is used less often. MRI scans can help tell if a uterine tumor looks like cancer, but a biopsy is still needed to tell for sure.
MRI scans are also particularly helpful in looking for cancer that has spread to the brain and spinal cord.
MRI scans take longer than CT scans-- often up to an hour. You are placed inside a tube, which is confining and can upset people with claustrophobia. The machine also makes clicking or buzzing noises that some people may find disturbing. Most places provide headphones and music to block this sound.
Positron emission tomography scan
In the positron emission tomography (PET) scan, radioactive glucose (sugar) is injected into the patient's vein. Because many cancers use glucose at a higher rate than normal tissues, the radioactivity will tend to concentrate in the cancer. A scanner can spot the radioactive deposits. This test can be helpful for spotting small collections of cancer cells. It may also help tell if a tumor is benign or malignant. PET scans are not routinely used to work-up a pelvic mass or abnormal bleeding in patients who are not known to have cancer.
A regular (plain) x-ray of the chest may be done to see if a uterine sarcoma has metastasized (spread) to the lungs and as part of the testing before surgery.
Last Medical Review: May 12, 2014 Last Revised: February 15, 2016