Quiescent gestational trophoblastic disease is a form of gestational trophoblastic disease that is completely inactive, benign or quiescent. Hyperglycosylated hCG is the molecule made by cytotrophoblast cells that drives invasion or implantation and growth during pregnancy. When a pinhead mass remains after removal of hydatidiform mole, a spontaneous abortion due hydatidiform mole, or after choriocarcinoma or gestational trophoblastic neoplasm chemotherapy, the small mass may lack cytotrophoblast cells, it lacks the hyperglycosylated hCG growth and invasion signal, as such it is inactive, benign or quiescent. This is quiescent gestational trophoblast disease.
Commonly, a woman has spontaneous abortion or miscarriage of pregnancy. Three month later she is shown to be positive for hCG but not pregnant. Testing shows the absence of hyperglycosylated hCG. This is quiescent gestational trophoblastic disease following a spontaneously aborted or miscarried hydatidiform mole pregnancy. Quiescent gestational trophoblastic disease also follows dilation and curettage of a proven hydatidiform mole pregnancy, or chemotherapy of an invasive mole, choriocarcinoma or gestation trophoblastic neoplasm.
In the USA hCG Reference Service experience, a quiescent gestational trophoblast disease mass is usually too small to be seen by ultrasound, CT scan or MRI. Such a mass may produce hCG continually. Usually, quiescent gestational trophoblast disease may last for approximately 6 months, then the tissue dies or is aborted.
Unfortunately, in the USA hCG Reference Service experience, approximately 10.4% of quiescent gestational trophoblast disease cases lead to persistent hydatidiform mole, which needs to be treated with chemotherapy. Chemotherapy, however, cannot destroy a quiescent mass, this is because it does not grow and does not invade. All chemotherapy maybe ineffective.
In the USA hCG Reference Service experience with over 200 cases of quiescent gestational trophoblastic disease, serum hCG is never more than 230 mIU/ml in these cases. Quiescent gestational trophoblastic disease from a pregnancy failure is the most common reason for a woman to be positive for hCG outside of pregnancy.