Molar Pregnancy (hydatidiform mole)

Question 1

What is a molar pregnancy?

Answer 1

It is when there is a genetic error during the fertilization process that leads to the growth of abnormal tissue within the uterus

Question 2

What are the types of molar pregnancy? (2)

Answer 2

1. Complete mole (no fetal tissue, only trophoblastic tissue)
2. Partial mole (abnormal fetal tissue along with trophoblastic tissue)

Question 3

What causes a complete mole

Answer 3

is caused by a single sperm combining with an egg which has lost its DNA

Question 4

What is the genotype in a complete mole

Answer 4

is typically 46XX due to subsequent meiosis of fertilizing sperm but can also be 46XY

Question 5

How does a partial mole occur

Answer 5

occurs when an egg is fertilized by 2 sperms or, by sperm which replicates itself yielding the genotype of 69 XXY or 92 XXXY

Question 6

What are the clinical features of a complete molar pregnancy? (6)

Answer 6

1. Vaginal bleeding (painless 1st trimester bleeding)
2. Uterine enlargement greater than dates
3. High levels of β-hCG (confirmed pregnancy) which can cause B-hCG mediated endocrine conditions like:
   - ovarian theca lutein cysts
   - pre eclampsia < 20th week of gestation
   - hyperemesis gravidarum
   - hyperthyroidism (bcz the alpha subunit of hCG structurally resembles TSH)
4. lack of FHR
5. passage of vesicles with grape like appearance
6. pelvic pressure or pain

Question 7

How is complete molar pregnancy diagnosed (4)

Answer 7

1. Pelvic ultrasound
   - Ultrasound showing “snowstorm” or “cluster of grapes” appearance (echogenic mass interspersed with many hypoechogenic cystic spaces representing hydropic villi)
   - no fetal parts or heartbeat
   -absence of amniotic fluid
   -ovarian theca lutein cysts
2. Uterine dilation and evacuation (D&C)
   - Histopathological examination: diffuse hydropic villi, marked circumferential trophoblastic proliferation
3. chest xray in those with pulmonary symptoms
4. Extremely high β-hCG levels for gestational age (serum quantitative hCG)

Question 8

what are risk factors (4)

Answer 8

• prior molar pregnancy
• age <15 years and > 35 years (extremes of age)
• history of miscarriage and infertility
• ethnicity: asians, hispanics, american indians

Question 9

How do you treat a complete mole

Answer 9

immediate dilation and curettage (D&C) under general anesthesia

Question 9

What is the pathophysiology of a complete mole (3)

Answer 9

• there is hydropic degeneration of chorionic villi
• proliferation of cytotrophoblasts and syncytiotrophoblasts
• death of embryo

Question 10

how do you follow up a patient who got rx for complete mole (4)

Answer 10

• obtain a quantitative hCG titer 48hrs
• serial quantitative hCGs weekly until levels are normal for 3 consecutive weeks
• after hCG levels normalized, do serial quantitave hCGs monthly for 6 months
• barrier contraception should be used until hCG normalizes. Hormonal contraception may be used thereafter.

Question 11

b-hCG is higher in which molar pregnancy

Answer 11

comple molar pregnancy

Question 12

the risk of subsequent GTN is what and it is higher in which type of molar pregnancy

Answer 12

• 15%-20%
• complete

Question 13

what are clinical features of partial molar pregnancy (4)

Answer 13

1. vaginal bleeding
2. pelvic tenderness
3. no change in uterine size
4. B-hCG mediated endocrine conditions are less common

Question 14

how can you diagnose partial molar pregnancy (6)

Answer 14

1. Pelvic ultrasound:
   - fetal parts may be visualized
   - FHR may be detectable
   - amniotic fluid may be visualized
   - increased placental thickness
   - multicystic avascular hypoechoic or anechoic spaces- swiss cheese appearance
2. Uterine D&C
   - histopathological examination will show partial occurrence of hydropic villi, minimal trophoblastic proliferation

Question 15

how do you follow up patients with molar pregnancy in malawi (7)

Answer 15

1. All cases must be followed up for 2 years
2. Monthly follow up till pregnancy test is negative:
   - In the first year, follow up every 3 months.
   - In the second year, follow up after 6 months
3. Speculum exam of vagina and sub-urethral area for metastases
4. Bimanual pelvic exam
5. Counsel patient on importance of early antenatal care and order ultrasound to look for any recurrent mole.
6. Prescribe family planning
7. If the pregnancy test remains positive after 3 months(should have disappeared after 6 weeks post D&E) then order ultrasound to monitor for ovarian cyst or residual/invasive mole and CXR for metastases.

Question 16

what is the FIGO gestational trophoblastic neoplasia staging (4)

Answer 16

Stage 1: disease confined to the uterus

Stage 2: GTN extends outside uterus, but is limited to genital structures (adnexia, vagina, broad ligament)

Stage 3: GTN extends to the lungs, with or without genital tract involvement

Stage 4: All other metastatic sites

Question 17

what is a choriocarcinoma

Answer 17

a highly malignant GTN characterized by invasive, highly vascular and anaplastic trophoblastic tissue without villi

Question 18

choriocarcinoma has the tendency to metastasize to what (7)

Answer 18

1. lungs
2. vagina
3. CNS
4. liver
5. pelvis
6. GI tract
7. kidneys

Question 19

choriocarcinoma is preceded by what (3)

Answer 19

1. hydatidiform mole
2. spontaneous abortion or ectopic pregnancy
3. term or preterm gestation

Question 20

what is the pathophysiology of choriocarcinoma (2)

Answer 20

• malignant transformation of cytotrophoblastic and syncytiotrophoblastic tissue
• destructive growth into myometrium without chorionic villi- causing risk of hemorrhage and early metastasis

Question 21

what are the clinical features of choriocarcinoma (5)

Answer 21

it depends on disease extension and metastases location:
1. postpartum vaginal bleeding and inadequate uterine regression after delivery
2. metastases in the lungs:
- dyspnea
- cough
- hemoptysis
3. metastases in the brain:
- seizures
- headaches
4. metastases in the vagina:
- visible vascular lesions
5. B-hCG mediated endocrine conditions:
- hyperthyroidism
- theca lutein cysts

Question 22

how do diagnose choriocarcinoma (5)

Answer 22

1. pelvic examination
2. lab tests:
   - B-hCG which will be very high
   - renal, thyroid, and liver function tests
   Imaging :
3. pelvic ultrasound
   - mass of varying appearance (suggestive of hemorrhage and necrosis)
   - hypervascular on color doppler
   - multiple theca lutein cysts
4. chest x-ray:
   - looking for lung metastases
   - cannonball metastases (hematogenous spread- multiple nodules in the lung)
5. D&C
   - histopathologic exam wil show anaplastic cytotrophoblats and syncytiotrophoblasts without chorionic villi

Question 23

how do you treat choriocarcinoma (3)

Answer 23

1. methotrexate or dactinomycin
2. surgical: hysterectomy- may be indicated to stop bleeding from cancerous lesions or to excise distant metastases
3. monitor B-hCG levels for at least 12 months

Question 24

what is an invasive mole

Answer 24

a form of GTD characterized by the malignant transformation of an incomplete or complete mole

Question 24

what is the cause of the invasive mole (2)

Answer 24

the risk of progression to an invasive mole which depends on the type of hydatidiform mole: -complete mole: 15%-20% risk -incomplete mole: <5% risk

Question 25

what is the pathophysiology of the invasive mole (3)

Answer 25

- trophoblasts infiltrate the myometrium - causing increased risk of uterine perforation, intraperitoneal hemorrhage or infection - hematogenic dissemination leads to metastatic growth ( brain, lungs, liver)

Question 26

how do you diagnose an invasive mole (3)

Answer 26

1. lab tests- persistently high B-hCG after evacuation of a hydatidiform mole 2. Imaging: - pelvic USS- poorly defined uterine mass, with potential invasion into myometrium - consider chest x-ray if metastasis is suspected 3. D&C - histopathologic exam shows direct myometrial invasion by abnormal trophoblastic cells with hydropic chorionic villi

Question 27

how do you treat invasive mole (3)

Answer 27

1. methotrexate or dactinomycin 2. surgical: hysterectomy- may be indicated to stop bleeding from cancerous lesions or to excise distant metastases 3. monitor B-hCG levels for at least 12 months