Trophoblastic diseases are a group of disorders caused by changes in the trophoblast cells of the embryo, including staphyloma, erosive staphyloma, trophoblastic tumors, choriocarcinoma and a rare group of trophoblastic tumors of the placenta. It usually develops after pregnancy, so it is also known as gestational trophoblastic disease in medicine. Staphyloma is formed when the chorionic villi become blister-like and the trophoblastic layer is proliferated secondary to pregnancy, and it is common during the first 10-16 weeks of pregnancy when the uterus enlarges rapidly and becomes larger than the expected gestation period. The level of HCG in the blood is surprisingly high, and a grape-like anechoic area may be seen in the uterus on ultrasound. In contrast, gestational trophoblastic tumors can arise after spontaneous abortion, ectopic pregnancy or full-term delivery. Erosive staphyloma, also known as destructive choriocapillaris adenoma, is caused by local infiltration of the myometrium by the staphyloma. Choriocarcinoma is an invasive tumor, very malignant and widely metastatic, consisting of malignant trophoblast cells. Trophoblastic tumors located in the placental area tend to cause bleeding in their location within the myometrium, and it can infiltrate adjacent tissues and occasionally metastasize to other parts of the body.