Placental Site Trophoblastic Disease: The Basics

Placental Site Trophoblastic Disease or Tumor (PSTD) is a rare type of Gestational Trophoblastic Disease (GTD). Out of 100 cases of GTD, about 1 or 2 are PSTD. Trophoblasts are cells that are made during the first stage of pregnancy. They provide nutrients for the embryo and become part of the placenta. In PSTD, the trophoblasts form when the placenta attaches to the uterus.

PSTD is different from other types of GTD because it leads to low beta human chorionic gonadotropin (B-hCG). hCG is a hormone in your blood that tells when you are pregnant. This level can be low after a normal pregnancy, miscarriage (the loss of a pregnancy), or abortion (ending a pregnancy).

Risk Factors

The risks of PSTD are still being studied. PSTD can happen if you are of reproductive age and post-menopausal (after you have gone through menopause).

Signs and Symptoms

Some symptoms of PSTD are:

• Vaginal Bleeding.
• Amenorrhea (missing one or more menstrual periods).

Diagnosis

If you are thought to have PSTD, your provider will look at your health history and check your pelvis. You may have imaging tests done, such as CT scan, MRI, ultrasound, and X-ray. You may also have your blood and urine tested. 

Staging

The stages of the tumor are I (one) to IV (four). Stage I means the disease is only in your uterus. Stage 4 means the tumor has spread (metastasized) to other parts of your body. The stage of your PSTD can help decide what treatment is best for you.

For GTD, a scoring system is used with staging to find out your risk and which treatment is best. PSTD does not use this scoring system.

Treatment

PSTD is often treated with surgery. Surgery helps find, stage, and remove as much of the tumor as possible. Some of the common types of surgery and procedures are:

• Suction dilation and curettage (also called a “D and C”).
• Hysterectomy.

A lumbar puncture (LP) may be done to see if there are cancer cells in other parts of your body.

Chemotherapy may or may not be used to treat PSTD. Chemotherapy may be used if:

• The tumor has spread to areas other than the uterus.
• You may want to have more children in the future. If this is the case, suction dilation and curettage may be used with chemotherapy.

This article is a basic guide to PSTD. You can learn more about PSTD by visiting:

Surgical Procedures: Surgery and Staging for Placental Site Trophoblastic Disease.