top of page
BMCH Website Header.jpg

Vesicular Mole (Hydatidiform Mole)

Female Genital Tract

Vesicular Mole (Hydatidiform Mole)
A vesicular mole is an abnormal form of pregnancy resulting from a genetic error during fertilization, leading to the growth of non-viable tissue instead of a normal fetus. It is a type of gestational trophoblastic disease (GTD) characterized by the proliferation of trophoblastic tissue and fluid-filled cystic structures.
________________________________________
Types of Vesicular Mole:
1. Complete Mole:
o Results from the fertilization of an ovum without maternal DNA (empty egg) by one or two sperm.
o Karyotype: 46, XX (most common) or 46, XY.
o No fetal tissue is present.
2. Partial Mole:
o Results from fertilization of a normal ovum by two sperms or one diploid sperm.
o Karyotype: Triploid (69, XXX; 69, XXY; or 69, XYY).
o Contains abnormal fetal tissue alongside molar changes.
________________________________________
Clinical Features:
• Vaginal bleeding (most common symptom).
• Enlarged uterus for gestational age.
• Absence of fetal heartbeat in a complete mole.
• Excessive nausea and vomiting (hyperemesis gravidarum).
• Early onset preeclampsia (before 20 weeks of gestation).
• Elevated beta-hCG levels (much higher than normal for gestational age).
________________________________________
Gross Appearance:
• Swollen, translucent, grape-like vesicles (hydropic villi) that vary in size from a few millimeters to over a centimeter.
• These vesicles are filled with fluid and appear pale or whitish.
• In a complete mole, there are no fetal parts or membranes.
• In a partial mole, malformed fetal parts or tissues may be present, interspersed with the molar vesicles.

________________________________________
Microscopic Appearance:
1. Complete Mole:
o Diffuse trophoblastic hyperplasia involving all villi.
o Enlarged, edematous villi with central cistern formation (fluid-filled spaces).
o Absence of fetal blood vessels.
o Trophoblastic atypia with hyperchromatic nuclei.
2. Partial Mole:
o Focal trophoblastic proliferation affecting some villi.
o Irregular villi with a mixture of hydropic (swollen) and normal villi.
o Presence of fetal blood vessels, sometimes with nucleated red blood cells.
o Identifiable but malformed fetal tissue may be observed.
________________________________________
Diagnosis:
• Ultrasound: "Snowstorm" or "grape-like" appearance, absence of fetus in a complete mole.
• Beta-hCG: Significantly elevated levels.
• Histopathology: Confirms the diagnosis by identifying the gross and microscopic features.
________________________________________
Management:
• Evacuation: Suction curettage to remove the molar tissue.
• Beta-hCG Monitoring: Serial measurements to ensure complete resolution.
• Contraception: Recommended during follow-up to prevent pregnancy, which may obscure monitoring.
________________________________________
Complications:
• Persistent trophoblastic disease or gestational trophoblastic neoplasia (GTN).
• Rarely, progression to choriocarcinoma.
• Uterine perforation during treatment.
________________________________________
Prognosis:
With timely treatment and close follow-up, the prognosis is excellent, and most patients recover fully without long-term complications.

bottom of page