Trophoblastic Disorders

Trophoblastic disorders Normal Trophoblast Villi penetrate into maternal tissue forming branching networks Distal branches are contained within a lobule into which the maternal spiral artery flows Trophoblastic cells can embolise into maternal circulation (have limited life so not malignant) All trophoblast cells secrete hCG which is used to monitor progress Hydatidiform Mole (any of the below) Tumour of trophoblastic villi 0.5-2/1000 pregnancies (higher risk in blood group A) Most will miscarry spontaneously so present as pain & PV bleed Can also present with large for dates uterus @ scan Excess hCG can à hyperemesis or early onset pre-eclampsia Partial Mole 23 maternal & 46 paternal chromosomes (2 sperm enter ovum) Embryo or fetus often dies in first or early 2nd trimester Hyperplasia and swelling of villi. 1% become invasive but transformation to choriocarcinoma is rare 0.5% require chemo after surgical removal Complete mole Mostly 46XX (but androgenically diploid). No embryo, membranes or cord – just hyperplasia & gross swelling of villi. Looks like a bunch of grapes 10% become invasive, 3% progress to choriocarcinoma 15% require chemo after surgical removal Snowstorm appearance on USS (solid with vesicles) Invasive mole Villi penetrate into myometrium & its blood vessels Can met to lung, vagina, liver, brain, GI tract Persistant hCG or ongoing bleeding after STOP Choriocarcinoma 1/50,000 pregnancy (50% after molar, 30% after miscarriage, 20% after normal pregnancy) Malignant – lacks villous structure. Agressively invades maternal muscle & blood vessels. Distant mets common. Lung (haemoptysis), brain (focal neurology), GI (blood loss or melaena), liver (jaundice) or kidney (haematuria) Presentation 8-24 weeks (peak 14) Bleeding, passing vesicles, pain, excess vomiting, hypertension, thyrotoxicosis (HCG is similar to thyroxine so similar effects), large for dates uterus, grape appearance on USS Management History + physical examination CXR Serum hCG Check maternal & paternal blood group & Rh status Crossmatch maternal blood prior to theatre Surgical evacuation under anaesthesia (risks bleeding & perf) Follow-up Monitor hCG closely until prolonged period of 0 Report to London/Sheffield/Dundee Advise not to get pregnanct for at least a year (only use COCP after hCG returned to normal) Risk of subsequent moles is 2% after one, and 20% after two Chemotherapy If hCG progressively rises after uterine evacuation or if > 20 000 IU/l at 4 weeks or if choriocarcinoma Regimes based on age, previous preg date, hCG level, blood group, tumour size, mets and previous chemo 80% respond to low dose methotrexate, 20% will be methotrexate resistant