Gestational Trophoblastic Neoplasia

Published on 10/03/2015 by admin

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Last modified 10/03/2015

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Chapter 42 Gestational Trophoblastic Neoplasia

Gestational trophoblastic neoplasia (GTN) represents a unique spectrum of diseases that includes benign hydatidiform mole; invasive mole (chorioadenoma destruens), which can metastasize; and the frankly malignant variety, choriocarcinoma. Most molar pregnancies are sporadic, but a familial syndrome of recurrent hydatidiform mole has been described. Future research should lead to identification of the genetic defect responsible for this uncommon syndrome.

Most patients (80% to 90%) with GTN follow a benign course, with their disease remitting spontaneously. Most patients with metastatic disease can be effectively cured with chemotherapy. This diverse group of diseases has a sensitive tumor marker, human chorionic gonadotropin (hCG), which is secreted by all these tumors and allows accurate follow-up and assessment of the disease.

image Genetics of Gestational Trophoblastic Disease

The cytogenetic analysis of tissue obtained from molar pregnancies offers some clue to the genesis of these lesions. Figure 42-1 illustrates the genetic composition of molar pregnancies.

image Classification

The term gestational trophoblastic neoplasia is of clinical value because often the diagnosis is made and therapy instituted without definitive knowledge of the precise histologic pattern. GTN may be benign or malignant and nonmetastatic or metastatic (Box 42-1).

The benign form of GTN is called hydatidiform mole. Although this entity is usually confined to the uterine cavity, trophoblastic tissue can occasionally embolize to the lungs. The malignant forms of GTN are invasive mole and choriocarcinoma. Invasive mole is usually a locally invasive lesion, although it can be associated with metastases. This lesion accounts for most patients who have persistent hCG titers following molar evacuation. Choriocarcinoma is the frankly malignant form of GTN.

Metastatic GTN can be subdivided into good prognosis and poor prognosis groups, depending on the sites of metastases and other clinical variables (Box 42-2).

image Hydatidiform Mole


Most patients with hydatidiform mole present with irregular or heavy vaginal bleeding during the first or early second trimester of pregnancy (Box 42-3). The bleeding is usually painless, although it can be associated with uterine contractions. In addition, the patient may expel molar “vesicles” from the vagina and occasionally may have excessive nausea, even hyperemesis gravidarum. Irritability, dizziness, and photophobia may occur because some patients experience preeclampsia. Patients may occasionally exhibit symptoms relating to hyperthyroidism, such as nervousness, anorexia, and tremors.