| Abstract: |
There is a spectrum of pregnancy-related trophoblastic proliferative abnormalities that arises from the trophoblast, the classification of which was based on histological criteria and included hydatidiform mole, invasive mole and choriocarcinomal placental site trophoblastic tumor, epithelioid trophoblastic tumor.Gestational trophoblastic neoplasia is affected by certain factors which are:- Geographic distribution with highest rates in certain areas oif Asia.- Parental age:• Maternal age: A significant increase in the incidence of mole in women 15 years old or younger and 40 years old or older.• Paternal age: A fourfold increase in risk to father aged over 45 years.- Parity: There appears to be no difference in parity among patients with molar pregnancies.- Nutritional factors: A deficiency of animal fat and fat-soluble vitamin carotene may contribute to this tumor.- Previous molar pregnancy: Patients with molar pregnancies have an increased risk of trophoblastic tumor in later conceptions.Gestational trophoblastic tumors result from an abnormal proliferation of different types of trophoblasts. Hydatidiform moles represent malformed placentas caused by genetic aberrations of the villous trophoblast. A complete mole displays a hyDROPic degeneration of all the chorionic villi with a more or less marked proliferation of trophoblasts. A partial mole is made up of molar vesicles interspersed with normal chorionic villi. In an invasive mole, molar vesicles penetrate the myometrium giving rise to a mass distorting the uterine wall.Choriocarcinoma is a very highly malignant tumor of GTN. It may follow hydatidiform mole, ectopic pregnancy, abortion or normal pregnancy.Choriocarcinoma is classified into low-risk, medium-risk, high-risk group according to scoring system which is based on many prognostic factors such as age, parity, type of antecedent pregnancy, blood group, site of metastases and response to chemotherapy.It is appropriate to note that choriocarcinoma is a tumor not of the uterus but of the embryonic chorion. The diagnosis of choriocarcinoma cannot be established in curettage specimen, unless one can identify necrotic muscles, hemorrhage, and lack of villous pattern, associated with marked cellular atypia and proliferation. The predominant mode of extention is via the vascular route.Cytogenetic studies of complete molar pregnancies have identified the chromosomal composition most often to be 46XX with the chromosomes completely of paternal origin.Most partial moles are triploid and indeed, most triploid appears to be partial mole. Partial moles have a maternal contribution, and dispermy appear to be the moist likely explanation for triploidy. Most partial moles that are triploid have a 69XXY, or 69XXX chromosome constitution.Techniques such as flow cytometry have been useful in distinguishing between diploid complete mole and triploid partial mole.Clinically, all patients with GTN, essentially have delayed menses for varying periods. Vaginal bleeding, nausea and vomiting occur, usually during the first trimester or irregular vaginal bleeding with subinvolution of the uterus which occur after labour (choriocarcinoma). In about half (50%) of the cases, uterine size clearly exceeds that expected from the duration of gestation, but the uterine size in the rest 50% is equal or smaller than gestational age.Prominent theca lutein ovarian cyst (> 6 cm in diameter) develop in about half of our patients with GTN. The cysts are usually multilocular, bilateral and contain amber-coloured fluid. These cysts may cause abdominal pain due to torsion or rupture, and commonly take up to 4 months to regress following treatment.Sonography plays a crucial role in diagnosing hydatidiform mole, in evaluating its progression to invasive mole or choriocarcinoma and in monitoring the efficacy of treatment. Duplex, Doppler, colour Doppler ultrasound, CT and MRI are also helpful in distinguishing trophoblastic tumor.Chest X-ray is important and easy method to demonstrate metastases in the lungs and pelvic arteriography which has also proven to be a useful and accurate way of localization of pelvic tumor.In trophoblastic tumor, human chorionic gonadotropins come closed to being the ideal tumor marker. Characteristically, hCG level in GTN is sustained and may be rising. So, repeated estimations are mandatory. The radioimmunoassay affairs a highly sensitivity method for monitoring of human chorionic gonadotropin in patients with gestational trophoblastic tumor.Treatment of benign tumor (hydatidiform mole) consists of two phases: immediate evacuation of the mole and subsequent follow-up for detection of persistent trophoblastic proliferation or malignant change
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