TYPES of GTD
There are various types of gestational trophoblastic disease. The most common is molar pregnancies. Other types include malignant forms-choriocarcinoma (placental cancer), placental site trophoblastic tumor, non-gestational choriocarcinoma, ephiliod trophoblastic tumor and quiescent GTD.
Molar pregnancies include both complete and partial hydatidiform moles, some are invasive. Some of these are persistent GTD, all of which hold chance to turn malignant.
Choriocarcinoma is a highly aggressive and fast growing malignant form of GTD usually from molar pregnancies, particularly complete, but can result form any pregnancy, miscarriage, termination, ectopic or left over fragments.
Chemotherapy is needed, single or multiple regimen, depending on metastasis, FIGO Score and Stage Level. Choriocarcinoma usually results from complete molar pregnancies but partial molars and left over placental fragments can also result into this malignant form of GTD, though more rare.
An even more rare form is Non-Gestational Choriocarcinoma which doesn't result from any gestational period and is usually on the ovary or teste (testicular choriocarcinoma). Pure form of ovarian choriocarcinoma is very rare. Male choriocarcinoma does not respond well to chemotherapy.
Placental Site Trophoblastic Tumor (PSTT)
PSTT is another rare form of GTD. This malignant type does not respond well to chemo unlike other GTD forms and a hysterectomy is usually needed. B-hcg levels are also low, opposite of other GTD forms. When chemotherapy fails, new treatments of stem cell transplant and immunotherapy are being used for cure in different countries, though extending more throughout. Cases of PSTT can come years after a pregnancy/childbirth and occurs after pregnancy and are slow growing.
Epithelioid Trophoblastic Tumor (ETT) and Quiescent GTD
Both very rare forms of GTD. ETT is malignant and speculated as either it's own form of GTD or "differentiating effects of treatment".
Quiescent GTD is "completely inactive, benign or quiescent"