Hydatidiform mole (or mola hydatidiforma) is a common complication of pregnancy, occurring once in every 1000 pregnancies in the US, with much higher rates in Asia (e.g. up to one in 100 pregnancies in Indonesia). It consists of a nonviable embryo which implants and proliferates within the uterus.  The term is derived from hydatidiform ("like a bunch of grapes") and mole (from Latin mola = millstone).
Most moles present with painless vaginal bleeding during the second trimester of pregnancy. They are diagnosed by ultrasound imaging. Extremely high levels of human chorionic gonadotropin (HCG) are suggestive, but not diagnostic, of molar pregnancy. Today moles are surgically removed by curettage, in order to avoid the risks of choriocarcinoma.
Hydatiform mole
Hydatidiform mole
Trichoadenoma
Mastitis
Mixed mullerian tumor
Struma ovarii
Hysteria
Chronic cystic mastitis