Epithelioid trophoblastic tumour

A rare type of gestational trophoblastic disease

Epithelioid trophoblastic tumour (ETT) is a rare form of gestational trophoblastic disease (GTD), which is a group of rare tumors that involve abnormal growth of cells inside a woman's uterus. ETT is characterized by the proliferation of intermediate trophoblastic cells that resemble carcinoma cells.

Pathophysiology

ETT arises from the intermediate trophoblast, which is a type of cell that forms part of the placenta during pregnancy. These cells are responsible for anchoring the placenta to the uterine wall. In ETT, these cells undergo neoplastic transformation, leading to the formation of a tumor. The tumor cells in ETT are typically monomorphic and epithelioid in appearance, which means they resemble epithelial cells.

Clinical Presentation

Patients with ETT may present with irregular vaginal bleeding, which is the most common symptom. Other symptoms can include an enlarged uterus, pelvic pain, or symptoms related to metastasis if the disease has spread. ETT can occur months to years after a pregnancy, including normal pregnancies, miscarriages, or molar pregnancies.

Diagnosis

The diagnosis of ETT is challenging due to its rarity and the overlap of its features with other types of GTD. Diagnosis typically involves a combination of clinical evaluation, imaging studies, and histopathological examination. Ultrasound and MRI may be used to assess the extent of the disease. Histologically, ETT is characterized by nests and cords of monomorphic intermediate trophoblastic cells with abundant eosinophilic cytoplasm and distinct cell borders.

Treatment

The primary treatment for ETT is surgical removal of the tumor, often through a hysterectomy. Due to the potential for metastasis, additional treatments such as chemotherapy may be considered, especially in cases where the disease has spread beyond the uterus. The choice of chemotherapy regimen can vary, but it often includes agents used in the treatment of other forms of GTD.

Prognosis

The prognosis for patients with ETT depends on several factors, including the stage of the disease at diagnosis and the presence of metastasis. Early-stage ETT that is confined to the uterus and treated with surgery generally has a good prognosis. However, metastatic ETT can be more challenging to treat and may have a poorer outcome.

Related pages

• Gestational trophoblastic disease
• Choriocarcinoma
• Placental site trophoblastic tumor
• Hydatidiform mole