Table of Contents
Page created on June 8, 2021. Last updated on January 14, 2022 at 15:59
Definition and epidemiology
Gestational trophoblast neoplasia (GTN) is a malignant type of gestational trophoblastic disease, a condition caused by pathological proliferation of trophoblasts. It’s sometimes called just malignant gestational trophoblastic disease.
GTN may arise from a hydatidiform mole, abortion, or normal pregnancy.
They’re rare but they are the most malignant cancers of the female genital tract. However, cure is still highly likely (> 80%).
Risk factors
- Old age
- Previous gestational trophoblastic disease
- Pathologic eggs
- Vitamin A deficiency
- Dietary protein deficiency
Classification
- Invasive mole
- Choriocarcinoma
- Placental site trophoblastic tumour
- Epithelioid trophoblastic tumour
An invasive mole is a hydatidiform mole which is invasive and has excessive trophoblastic proliferation. It invades into the myometrium, penetrating the uterine wall, and metastasises through the circulation. Metastasis is most often to the lung.
Choriocarcinoma is a highly malignant gestational trophoblast neoplasia. The main difference between invasive moles and choriocarcinoma is that there is no villous pattern in choriocarcinoma. The tumour appears as an irregular haemorrhagic growth in the uterine walls. It grows quickly and metastasises early.
Clinical features
GTN may present in various ways:
- Patients who underwent treatment for molar pregnancy and the β-hCG monitoring has shown a stagnation or increase in the hormone
- Patients may present with continuing amenorrhoea or inadequate uterine regression after a molar or a normal pregnancy
- Patients may present with symptoms of lung metastasis, like coughing or haemoptysis.
- Patients may experience hyperthyroidism due to the high hCG level
- Patients may present with symptoms of vaginal metastasis, like vaginal bleeding
Diagnosis and evaluation
On ultrasound, the uterus is enlarged compared to the gestational age. Bilateral theca lutein cysts of the ovary may be present. Bilateral enlarged ovaries with theca lutein cysts may be present. Ascites and pleural fluid may be present due to ovarian hyperstimulation. Ultrasound may also show a highly vascularised mass in the uterus.
The hCG concentration is significantly higher than normal, and no foetal vital signs can be detected.
Chest metastases are common, and all patients suspected to have GTN should undergo chest x-ray.
Treatment
Treatment of invasive mole is the same as for choriocarcinoma.
The prognosis of choriocarcinoma has improved since the introduction of chemotherapeutic drugs. The first choice is methotrexate alone or in combination with actinomycin D. In case of liver or kidney dysfunction, actinomycin D may be used alone.
Serum β-hCG must be monitored for 1 – 2 years after the treatment to make sure there is no recurrence. Normalisation of the values may take months. If the values stop decreasing, or they start increasing, a recurrence is likely. In these cases, hysterectomy is performed.