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Gestational Trophoblastic Disease

Q: What nosological forms are included in the classification of gestational trophoblastic disease?

Simple hydatidiform mole — a benign form of the disease with a risk of malignant transformation.Invasive mole (Invasive mole) — a malignant trophoblastic tumor with invasion into the myometrium.Choriocarcinoma (Choriocarcinoma) — a malignant tumor originating from the trophoblastic epithelium.Placental site trophoblastic tumor (Placental site trophoblastic tumor) — a rare tumor originating from intermediate trophoblasts.Epithelioid trophoblastic tumor (Epithelioid trophoblastic tumor) — a malignant form of gestational trophoblastic disease.

*Morbus trophoblasticus*

For medical students2 min readUpdated 2026-10-10

Gestational trophoblastic disease encompasses a group of pathological conditions developing from the trophoblastic epithelium after pregnancy. It includes both benign forms and malignant tumors requiring timely diagnosis based on hormone levels.

Disease markerHigh level of human chorionic gonadotropin in the blood

ChoriocarcinomaMalignant tumor derived from cyto- and syncytiotrophoblasts

MetastasisEarly hematogenous metastasis to the lungs, brain, and liver

Invasive moleVillus penetration into the myometrium without signs of true malignancy

Hydatidiform Mole and Invasive Forms

A hydatidiform mole is the most common form of the pathology. After tissue removal, the recovery risk is high, but there is a possibility of transformation into choriocarcinoma.

Complete hydatidiform mole: the risk of malignant transformation is about 5%.
Partial hydatidiform mole: the risk is significantly lower.
Invasive mole: characterized by the penetration of villi into the myometrium. It is important to note that invasive growth here is not an absolute sign of malignancy, as normal trophoblasts also possess invasive properties.

Choriocarcinoma: Malignant Potential

This is an aggressive tumor lacking its own stroma and blood vessels. It grows rapidly, causing extensive necrosis and hemorrhage.

History: develops in 50% of cases after a hydatidiform mole, in 25% after an abortion, and in 22.5% after a normal pregnancy.
Clinical features: can manifest even 15–20 years after the completion of pregnancy.
Metastasis: the tumor is prone to early hematogenous spread to the lungs, vagina, kidneys, and brain.

Placental Site Trophoblastic Tumor

A rare form consisting predominantly of intermediate trophoblasts. Unlike choriocarcinoma, this tumor is not characterized by prominent necrosis and hemorrhage. The tumor cells secrete placental lactogen, and macroscopically it appears as polypoid masses within the myometrium.

Mnemonic

Trophoblast has three layers: Cytotrophoblast, Syncytiotrophoblast, and Intermediate trophoblast. Remember that choriocarcinoma is a 'homeless' tumor: it lacks its own stroma and vessels, which is why it 'runs' (metastasizes) so quickly through the blood.

Frequently asked questions

What nosological forms are included in the classification of gestational trophoblastic disease?

Simple hydatidiform mole — a benign form of the disease with a risk of malignant transformation.
Invasive mole (Invasive mole) — a malignant trophoblastic tumor with invasion into the myometrium.
Choriocarcinoma (Choriocarcinoma) — a malignant tumor originating from the trophoblastic epithelium.
Placental site trophoblastic tumor (Placental site trophoblastic tumor) — a rare tumor originating from intermediate trophoblasts.
Epithelioid trophoblastic tumor (Epithelioid trophoblastic tumor) — a malignant form of gestational trophoblastic disease.

Is invasive growth of villi into the myometrium a sign of cancer?

No, invasive growth in a hydatidiform mole is not a sign of true malignancy because normal trophoblasts also have the ability to deeply penetrate the myometrium.

What tissues make up choriocarcinoma?

The tumor consists of atypical cytotrophoblast cells and multinucleated giant syncytiotrophoblast elements.

Why does choriocarcinoma give early metastases?

Due to its growth pattern: the tumor rapidly destroys tissues, invades blood vessels, and lacks its own stroma, which facilitates the detachment of tumor cells and their hematogenous spread.

Go deeper

Physiological functions of the placenta and barrier mechanisms.
Classification of placental inflammatory processes (deciduitis, villitis, intervillitis).
Routes of placental infection: ascending and hematogenous.
Pathogenesis of preterm labor in chorioamnionitis.
Complications of funisitis and their impact on the fetus.