Gestational Trophoblastic Neoplasia

Introduction
A molar pregnancy occurs when a fetus is not able to fully form in the uterus. Instead, the fetal tissue becomes a tumor.

What is going on in the body?

In the US, a molar pregnancy occurs in 1 out of every 2,000 pregnancies. In this condition, fetal cells have an abnormal genetic makeup and form a tumor. This tumor, or "mole," can grow and even spread to other parts of a mother's body. In some cases, the mole may turn into a more dangerous cancer called choriocarcinoma.

What are the causes and risks of the condition?

In this condition, abnormal fetal tissue inside a woman's uterus forms a tumor. The exact reason this occurs is not known. Common risk factors for this condition include:

a recent full-term pregnancy, abortion, miscarriage, or ectopic pregnancy

a previous molar pregnancy

being of Asian or Mexican descent

being younger than 20 or older than 40 years of age

being poor

a diet that is low in protein, folate, or beta-carotene   

What are the signs and symptoms of the condition?

Common symptoms of this condition may include:

vaginal bleeding during pregnancy or shortly after a pregnancy, miscarriage, or abortion

severe nausea and vomiting, often bad enough to require treatment in the hospital

a uterus that grows slower or faster than normal during pregnancy

symptoms from an abnormally high level of thyroid hormone, also called hyperthyroidism

high blood pressure that begins for the first time in the first trimester. This may mean that preeclampsia, also called toxemia of pregnancy, is present.

symptoms of the tumor or cancer spreading to other organs. For example, coughing up blood may occur if the tumor goes to the lungs, or abdominal pain if the tumor goes to the liver. 

How is the condition diagnosed?

Diagnosis begins with a history and physical exam. There is usually a history of a recent pregnancy, whether or not a child was born. A blood test is done to measure the level of HCG, the "hormone of pregnancy." In a molar pregnancy, the level of HCG becomes too high because of the abnormal fetal tissue.
If the level of HCG is abnormally high, an ultrasound can help locate and confirm the tumor. A chest x-ray or MRI or CT scan of different parts of the body may be done if the healthcare provider suspects that the tumor has spread to other organs. 

What can be done to prevent the condition?

Women are advised to get enough folate, carotene, and protein in their diet before becoming pregnant. This may decrease the risk of this condition.
Early diagnosis improves the chance of cure, though it cannot prevent this condition. Any woman with abnormal vaginal bleeding or other unusual symptoms after pregnancy should see her healthcare provider.

What are the long-term effects of the condition?

In most cases, treatment results in a cure and there are few long-term effects. However, the tumor can spread to other areas of the body, which may result in organ damage and even death.

What are the treatments for the condition?

In most cases, the main treatment is a procedure called a dilation and curettage (D&C). This involves removing all the contents of the inside of the uterus with a special tool. In women who do not want any more children, a hysterectomy, or the removal of the uterus, may be advised.
If the tumor has spread to other areas of the body, chemotherapy and sometimes radiation therapy is usually advised.

What are the side effects of the treatments?

If a hysterectomy or a D&C is done, the side effects may include bleeding, infection, and scarring of the uterus. Chemotherapy can cause stomach upset, nausea, weakness, and other side effects.

What happens after treatment for the condition?

A woman is advised to take it easy for a few days after a D&C. A hysterectomy usually requires a few weeks of recovery. The woman should be alert for any unusual bleeding after surgery.
After all types of treatment, the level of HCG in the blood is checked regularly to make sure it returns to normal. If the level of HCG stays high or becomes high again in the future, this may mean that the tumor has spread or come back. Birth control should be used for at least 1 year after treatment. This is because pregnancy, by raising the level of HCG, can make it hard to detect if the tumor has come back.  

Reference
Understanding Your Body, Felicia Stewart, Felicia Guest, Gary Stewart, and Robert Hatcher, 1987

Maternity and Gynecological Care, The Nurse and the Family, Irene Bobak, Margaret Jensen, Marianne Zalar, Mosby Co., 1989