The document discusses gestational trophoblastic diseases, including complete and partial hydatidiform moles, which are benign tumors characterized by abnormal trophoblastic cell proliferation due to abnormal fertilization. It details the incidence, risk factors, clinical presentations, and pathological features of each type. Additionally, it outlines choriocarcinoma, a malignant tumor that can arise from complete moles, including its incidence, presentation, and microscopic characteristics.

1. Manal Ismail Abd-Elghany
Associate Professor of Pathology, PhD (UK),
MD(Egypt)
Trophoblastic Diseases

2. GESTATIONAL
TROPHOBLASTIC DISEASES

3.  Definition: Gestational trophoblastic disease (benign
tumor of the chorionic villus) resulting from abnormal
fertilization of an ovum and characterized by abnormal
proliferation of trophoblastic cells. It is also called vesicular
mole.
 The incidence: is 7–10 times higher in Southeast Asian
countries than in the Western world. Occurs in 1 of 1500
pregnancies in the United States.
 Risk factors: Increased maternal age is only a risk factor
for complete mole and not partial mole.
 Types: Hydatidiform moles are classified into two different
types:
A. Complete mole
B. Partial mole
1
Hydatidiform Mole

4.  A. Complete mole:
 Results from fertilization of an empty ovum by two sperms
or a haploid sperm that divides its nuclear material and
forms diploid chromosomes (46,XX or 46,XY).
 Therefore, the complete mole is completely paternal in
origin.
 Fetal parts are completely absent.
 The placenta is completely neoplastic.
 B. Partial mole:
 Results from fertilization of a normal ovum by two sperm
cells or duplication of one sperm. It has triploid
chromosomes (69,XXY, 69,XXX, or 69,XYY).
 Partial mole is both maternal and paternal in origin and
partially consists of identifiable fetal parts.
 Not all placental villi are neoplastic. 2

5. 3a

6. 3b

7.  Presentation:
A. Complete mole:
 The most common presentation is first-trimester
vaginal bleeding.
 Additional features include mainly excessive
elevations in hCG, excessive uterine size,
symptoms of preeclampsia in the first trimester
& hyperthyroidism.
B. Partial mole:
 The most common presentations include:
vaginal bleeding or the features of missed or
incomplete abortion.
 The uterus is usually small for date. 4

8.  Pathological features of Complete mole:
 Grossly:
 The uterus is enlarged and characteristically filled
with grape-like vesicles. The vesicles contain clear
watery fluid.
 Microscopically:
 Large & edematous villi due to hydropic
degeneration.
 Stroma is avascular.
 Trophoblastic proliferation in both cytotrophoblast
and syncytiotrophoblast, generally circumferential
around the villi i.e. diffuse. 5

11. Complete mole

12. Complete mole

13.  Pathological features of Partial mole:
 Grossly:
 The uterus contains some cystic villi.
 Part of the placenta appears normal.
 A fetus with multiple malformations is often present.
 Microscopically:
 Some of the villi show edematous change while
others are normal or even fibrotic.
 Trophoblastic proliferation is usually slight & focal.
6

14. slide 3 of 3
Partial mole. A fetus is present (he
had
malformations).

15. Partial mole
 Heterogeneity in villous size with 2 discrete populations:
1. Large, hydropic villi &
2. Small, normal, fibrotic villi

16. Partial mole

17. 7
First Aid for The Basic Sciences Organ Systems (2017): Reproductive, Chapter 9,
3rd ed. page 711.

18. Choriocarcinoma

19.  Definition:
 Choriocarcinoma is an aggressive, malignant tumor arising
from gestational chorionic epithelium.
 Incidence:
 It usually follow evacuation of a mole, with 2% of complete
moles becoming choriocarcinoma.
 Presentation:
 Recurrent vaginal bleeding after evacuation of a complete
mole or following delivery, ectopic pregnancy, or abortion.
 Levels of hCG continue to rise after evacuation.
 Metastases:
 Spread hematogenously to the lung (50%), vagina (35%),
liver, and brain.
8

20.  Grossly:
 It appears as fleshy or soft, hemorrhagic,
necrotic masses within the uterus.
 Microscopically:
 Choriocarcinoma has a distinctive biphasic
appearance consisting of mononucleated
trophoblastic cells (with clear cytoplasm)
and multinucleated syncytio-
trophoblasts (with deeply eosinophilic
cytoplasm). There are no chorionic villi.
9

22. slide 7 of 105
Choriocarcinoma

23. Abnormal Uterine Bleeding
“AUB”

24. Abnormal Uterine Bleeding AUB (according to age group)
10

25. 11

26. Abnormal Uterine Bleeding (AUB)
PALM COEIN