GTD Flashcards
What WHO scores are counted as low risk GTN?
< 7
WHat WHO scores are counted as high risk GTN?
7 - 13
What WHO scores are considered extremely high risk?
> 13
What are the founr types of malignant GTN?
malignant invasive mole, Choriocarcinoma, placental site trophoblastic tumour (PSTT) and Epitherlioid trophoblastic tumour (ETT)
What is the significance of an atypical placental site nodule?
10 - 15% may coexist with or develop into PSTT / ETT
What % of cases of CHM will develop into GTN?
15-20%
What % of PHM will develop into GTN?
0.5 - 5%
What is the incidence of hydatidiform mole
1: 1000 and 1-3: 1000 in developed countries
What is the incidence of partial mole?
3: 1,000 pregnancies
RF for GTD?
Extremes of reproductive age <15 & >45
Hx of molar pregnancy - 10x risk after 1
Even more after 2.
Dietary deficiency of beta-carotene and animal fat is considerd to be a etiological factor for complete mole but not partial mole.
What is quiescent GTN?
Consistently low level of hCG; <200 mIU/mL)
persists for > 3 months after evacuation without detectable disease.
Very rare
? due to small focus of highly differentiated, noninvasive syncytiotrophoblast cells that produce small amounts of hCG and usually do not progress to invasive disease as long as cytotrophoblast or intermediate cells are absent.
Do not require Rx. 6 - 10 % will eventually develop active GTN, Monitor and avoid pregnancy.
quiescent GTN is far less common than active GTN after a molar pregnancy, patients who develop a persistent plateau or elevation of hCG at low levels during HM follow-up may reasonably be diagnosed with active GTN and treated.
Evidence of chemotherapy resistance (hCG level unresponsive to therapy presumably because the growth cycle of these cells is long and comparable to normal cells) combined with absence of any clinical or radiologic evidence of GTN supports the diagnosis of quiescent GTN and should prompt discontinuation of chemotherapy unless active GTN is documented by increasing hCG levels. Measurement of hyperglycosylated hCG (hCG-h) has been proposed for surveillance in patients with quiescent GTN, but the test is not commercially available.
What is a trophoblast?
Trophoblasts (from Greek to feed: threphein) are cells forming the outer layer of a blastocyst, which provides nutrients to the embryo, and develops into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg.
What is a villous trophoblast?
Villous trophoblast cells consist of progenitors referred to as cytotrophoblast, which fuse to form syncytiotrophoblast
What are syncytiothrophoblasts?
syncytiotrophoblasts are a continuous, specialized layer of epithelial cells. They cover the entire surface of villous trees and are in direct contact with maternal blood. The surface area of syncytiotrophoblasts is about 5 square meters at 28 weeks’ gestation and reaches up to 11–12 square meters at term
Syncytiotrophoblast represent both the primary barrier regulating transport between maternal and fetal vascular compartments and, also the principal source of steroid and peptide hormones produced by the human placenta.
What are cytotrophoblasts?
Beneath the syncytiotrophoblasts are the cytotrophoblasts. Considered to be stem cells for syncytiotrophoblasts.
Continually differentiate into syncytiotrophoblasts during villous formation and development. Cytotrophoblast invasion into the uterine spiral arteries is accompanied by loss of the endothelial lining and musculoelastic tissue in these vessels. This process of invasion is necessary for placental vascular remodelling in the early stages of the implantation process.
