GTD Flashcards
How commonly does GTN develop after a complete and partial mole?
Complete 15-20%
Partial 0.5-5%
What type of pregnancy does GTN follow?
what are the rates?
50% occur after molar pregnancies, the rest after spont abortion, Ectopic, or term pregnancy
How common is molar pregnancies?
How common is choriocarcinoma?
1/714 live births. Higher occurrence is Asian women
FIGO says 1:1000
Choriocarcinoma 1-10 : 40 000
What are the risk factors for developing GTD
Extremes of age (as abnormal gametogenesis and fertilization)
Risk increases after 35, 5-10X higher after 45
Previous GTD
Increases the risk of recurrence by 10X
Diets deficient in folate, protein and carotene
Women with blood group A with blood group O partners are at 10 times higher risk
Women with blood group AB have a worse prognosis
Women with theca lutein cysts are at higher risk of developing malignant sequalae
Dietary deficiency in beta carotene and animal fat is associated with complete moles
How does cytogenetics help differentiate between partial and complete molar pregnancies?
A cyclin dependent kinase inhibitor P57 is encoded by paternal imprinted and maternally expressed genes and therefore is absent in CHM. PHM and hydropic gestations have strong p57 staining. P57 stain can be use to exclude a complete mole
what is the gross description and histology of complete molar pregnancies?
Gross:
Hydropic villi to semi transparent vesicles of variable sizes with absence of normal placenta (if early may have no abnormal villi)
Histology: Florid cistern formation, trophoblastic proliferation in the absence of fetal parts, significant cytological atypia and mitotic figures are common.
In T1 Polypoid appearance, abnormal villous stromal changes and mild to moderate trophoblastic hyperplasia.
What is the pathology of a complete molar pregnancy?
Complete moles usually (75–80%) arise as a consequence of duplication of a single sperm following fertilisation of an ‘empty’ ovum.
Some complete moles (20–25%) can arise after dispermic fertilisation of an ‘empty’ ovum.
what is the pathology of partial moles?
(90%) triploid in origin, with two sets of paternal haploid genes and one set of maternal haploid genes.
Partial moles occur, in almost all cases, following dispermic fertilisation of an ovum.
Ten percent of partial moles represent tetraploid or mosaic conceptions
What is the histology of a partial mole?
Histo: changes less marked compared to partial mode and fetal parts or cells are present
Histology of a choriocarcinoma
gross description?
genetics?
The tumor is bulky with hemorrhagic and necrotic areas. It can be found in the tubes, ovaries, lung, liver, spleen, kidneys, bowel or brain.
Most XX with highly complex karyotypes
Histology: absence of chorionic villi and presence of abnormal intermediate trophoblast and cytotrophoblasts with necrosis and haemorrhage.
Placental site trophoblastic tumor
Gross description and histology
Grossly: white, tan to yellow nodular masses varying from 1-10 cm in the endomyometrium, half of the cases invade the myometrium.
Histo: mononuclear intermediate trophoblast on the maternal side of the vascular bed. Tumor cells have irregular nuclear membranes, hyperchromatic nuclei and dense eosinophilic cytoplasm. Most tumors have a low mitotic count. Chorionic villi are absent.
Tumor cells procedure human placental lactogen (hPL) MUC-4, HSD3B1, HLA-G and Mel-CAM (CD146) Focal expression hcg and inhibin. Proliferation index is modestly increased with Ki-67 expressed in 10-30% of cells, higher then benign exaggerated placental site reaction. These have rare genetic imbalances.
Epithelial trophoblastic tissue
Gross and histological description
Epithelial Trophoblastic tumor
Grossly: white tan to brown, discrete nodules or cystic haemorrhagic masses invading deep into the surrounding tissues. Half in the cx or lower segment, some in the fundus and the broad ligament.
Histo: arises from chorionic type intermediate trophoblast. Relatively uniform intermediate trophoblastic cells with moderate eosinophilic to clear cytoplasm and round nuclei are surrounded by extensve necrosis and associated hyaline like matrix. Extensive necrosis – can co exist with other trophoblastic neoplasms.
How does GTN present
irregular vaginal bleeding, hyperemesis, excessive uterine enlargement Early failed pregnancy Hyperthryoidism Early onset pre eclampsia Abdo distention to theca tutein cysts Respiratory failure and seizures After a pregnancy with symptoms of metastasis pulmonary sx, neurological signs, spine, brain, - GTD should be considered with unusual sx and + hcg
What does a molar pregancy look like on USS
Multiple hypoechoic cystic structures - snowstorm appearance
Honeycomb - Rarely seen T1
T1 often cystic spaces and absence of fetal parts, maybe a deformed sac
How to manage an a molar pregnancy
Suction curettage under USS guidance
Fertility preserving
12-14 mm suction cannular
IV oxytocin infusion is started at the onset and continued for hours afterwards to enhance uterine contractility.
If uterus over 16 weeks then blood should be avaliable
Rh immunoglobulin (RhD is expressed in trophoblasts)
If over 40 and not wanting uterus then for hysterectomy
- decreases the chance of subsequent chemo
