A 17 year old girl in the 4th month of pregnancy presents with vaginal bleeding, accompanied by passage of grapelike tissue fragments. Plasma human chorionic gonadotropin (hCG) is very high.Following ultrasound evaluation, dilatation and curettage is performed. Histologic examination shows diffuse trophoblastic proliferation and edema in all chorionic villi. Cytogenetic studies demonstrate 46, XY karyotype. Clinical studies show that this condition progresses to choriocarcinoma at a rate of?
The condition described is a complete hydatidiform mole. Hydatidiform mole is a spectrum of conditions due to abnormal proliferation of trophoblast and ranging from entirely benign conditions (complete and paial mole) to very aggressive neoplasms (choriocarcinoma). Paial moles have a triploid karyotype (69,XXY) and derive from feilization of an ovum with one or two sperm; fetal pas are frequently seen. Complete moles have a diploid karyotype (46,XX or 46,XY) and derive from feilization of an empty ovum by a single sperm (androgenesis); no fetal pas are found. Ten percent of moles acquire a more aggressive behavior and invade deeper pas of the myometrium, degenerating into invasive moles. Two percent of complete moles may transform into choriocarcinoma, a very aggressive neoplasm that spreads rapidly through the bloodstream. Founately, choriocarcinomas of placental origin are highly responsive to chemotherapy, affording up to 100% cure or remission. Nongestational choriocarcinoma, in contrast, is poorly responsive to chemotherapy. Remember the following impoant points: Complete mole, usually diploid karyotype: results from androgenesis (sperm feilization of an empty egg), no fetal pas are identified, 2% progress to choriocarcinoma. Paial mole, usually triploid karyotype: results from feilization of normal egg by one or two sperm; fetal pas are often identified; rarely progresses to choriocarcinoma. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 11. Gestational Trophoblastic Disease. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.
0.20%
2%
20%
50%