Gestational Trophoblastic Disease - Molar Pregnancies (Lecture 12)

What is GTD? What are the types?

Gestational trophoblastic disease

spectrum of diseases characterized by presence of abn proliferation of trophoblasts and includes complete and partial hydatidiform moles, placental site invasive moles, trophoblastic tumors and choriocarcinomas

Divided into 2 forms: benign and malignant

- hydatidiform moles = benign

- invasive mole, choriocarcinomas, placental trophoblastic tumour = malignant

What are the risk factors for GTD?

- Extremes in maternal age (less than 20, more than 35)

- Hx of prior GTD

- Southeast Asian origin

- Prior spontaneous abortion and infertility

What is a complete molar pregnancy? What is its CP? (HINT: 3) What are its SF?

- No maternal genetic material, all chromosomes are of paternal origin. Occurs when in meioisis, sperm fertilizes ovum and duplicates, making all chromosomes of paternal origin. This results in no fetus present (46XX usually).

- Placenta completely replaced by hydropic chorionic villi, causing diffuse hyperplasia, grape-like clusters of vesicles filled w/ gelatinous material, and no fetal blood vessels/tissue

- CP: vaginal bleeding, hyperemesis (inc vomitting) from inc bhCG, rapid uterine enlargement

- May see maternal anemia, hypetension. hyperthyroidism (from inc bhCG), theca lutein cysts

SF:

- in first trimester, palcenta appears solid w/ few cystic vesicles

- in 2nd trim: no fetus, echogenic mass w/ multiple cystic spaces (snowstorm/grape cluster), enalrged uterus, MAY see vasc (not always seen)

TRUE or FALSE: The key SF for CHM are that they always appear with no fetus and inc. vascularity.

FALSE: Vascularity may or may not be seen in CHM. The key SF for CHM is no fetus and an echogenic mass with cystic spaces (grape-like clusters)

What is the m/c type of GTD?

CHM (complete hydatidiform mole)

What is a partial molar pregnancy? What are the SF?

Partial hydatidiform mole (PHM)

- Normal ovum fertilized by 2 sperm, resulting in triploidy (3 copies of all 23 chromosomes = 69 chromosomes), creating a probable abn fetus with a molar placenta

SF:

- Placenta appears more "swiss-cheese" like (normal tissue b/w cysts)

- Fetus is seen (likely abn)

How do you differentiate endometrial hyperplasia from a CHM?

CHM = pt is pregnant

TRUE or FALSE: CHM may present with theca lutein cysts in the ovaries.

TRUE: This is due to the elevated bhCG levels.

What does a coexistent hydatidiform mole and normal embryo look like sonographically?

Complete mole + normal fetus --> twin gestation

SF:

- Twin peak sign - chorionic tissue b/w molar tissue and gs

- Normal placenta and fetus next to hydropic placenta (m/c)

What is the treatment and f/u or a CHM?

- Suction curettage (D&C): uterus evacuated

- Monitor bhCG levels for 1 yr to ensure they're gone (delay preg for 1 yr after a molar preg to avoid confusion b/w normal preg and recurrent disease)

What is the d/dx for a CHM?

Failed early pregnancy (blighted ovum, threatened abortion)

(Differentiate w/ pt history)

What is the d/dx for a PHM?

- Missed/incomplete abortion

- Mesenchymal dysplasia of placenta (benign placental vascular anomaly)

(Differentiate by doing histology, genetic testing, bhCG levels)

How do you differentiate b/w a PHM and a coexistent CHM with normal twin gestation?

- PHM = abn fetus and placenta

- Coexistent CHm w/ normal twin gestation = 1 abn fetus and placenta, 1 normal fetus and placenta