Invasive mole is a complication of molar pregnancy where abnormal villi grow into the myometrium or blood vessels. It occurs in approximately 15% of complete moles and can metastasize to other organs. Clinical features include persistent hemorrhage and uterine perforation. Microscopically, proliferating trophoblast tissue is seen invading the myometrium. Treatment involves chemotherapy, with single or combination drug regimens depending on the disease stage. The goals are to normalize hCG levels and administer additional "clean-up" courses of chemotherapy.

1. INVASIVE MOLE Dr. Margarita Isabel Amoroso-Artes Department of OB/GYN

2. Definition Molar pregnancy ChorioadenomaDestruens Molar villi grow into the myometrium or its blood vessels May extend into the broad ligament and metastasize to the lungs, the vagina or the vulva.

3. All cases of invasive mole are sequelae of hydatidiform moles Approximately 15% of complete moles are associated with or precede invasive moles The pathologic diagnosis of invasive mole is rarely made because most cases are treated medically, without hysterectomy

4. CLINICAL FEATURES PERSISTENT HEMORRHAGE UTERINE PERFORATION

5. Vascular invasion may result in trophoblastic nodules in sites outside the uterus, such as: vagina lungs

6. Hydropicvilli covered by proliferating trophoblast are seen permeating the myometrium in this invasive mole

7. Gross appearance of invasive mole. A hemorrhagic mass has permeated half of the thickness of the myometrial wall.

8. Whole-mount view of invasive mole. Abnormal villi are seen permeating the thickened myometrium (arrows).

9. Invasive mole vs complete mole DIFFERENTIALS

10. Large villi with stromaledema and marked trophoblastic proliferation Diagnostic Pearls Nearly all of the villi show hydropic degeneration appearing as a 'bunch of grapes', vesicles measure 1 to 30 mm, and no embryo, fetus , membranes or cord is seen There is vesicular swelling of the villi and hyperplasia of the trophoblast Trophoblastic hyperplasia has a circumferential arrangement around each villi Abnormal villi with proliferating trophoblast invading the myometrium Diagnostic Pearls Hemorrhagic mass permeating the myometrial wall Abnormal villi are seen permeating the myometrial wall or inside blood vessels The vascular invasion may result in nodules outside the uterus

11. INVASIVE MOLE VS PARTIAL MOLE DIFFERENTIALS

12. Scalloping of the villi and pseudoinclusion of trophoblastic tissue Diagnostic Pearls Less placental tissue than in complete mole, with a mixture of normal villi and large vesicles, an embryo or a fetus may be found Mixture of large and small villi, with focal edema to cisterna formation Many of the villi have an irregular, scalloped outline and contain vessels with fetal red blood cells Abnormal villi with proliferating trophoblast invading the myometrium Diagnostic Pearls Hemorrhagic mass permeating the myometrial wall Abnormal villi are seen permeating the myometrial wall or inside blood vessels The vascular invasion may result in nodules outside the uterus

13. INVASIVE MOLE VS CHORIOCARCINOMA DIFFERENTIALS

14. Admixture of syncytiotrophoblast and cytotrophoblast is seen in this example Diagnostic Pearls Clusters of cytotrophoblast separated by streaming masses of syncytiotrophoblast, with a characteristic dimophicplexiform pattern Villi formation must be absent Vascular invasion is commonly found and may be extensive Abnormal villi with proliferating trophoblast invading the myometrium Diagnostic Pearls Hemorrhagic mass permeating the myometrial wall Abnormal villi are seen permeating the myometrial wall or inside blood vessels The vascular invasion may result in nodules outside the uterus

15. Figo Staging

16. MANAGEMENT CHEMOTHERAPY PRIMARILY

17. Stage I, Stage II-III low risks patients Single Agent every 7- 10 days 2 clean-up courses after the first normal titer Discontinue Chemotherapy/shifted to another regimen: (actinomycin D) (+) toxicity Drug resistance

18. Stage II-III, High Risk Combination of chemotherapy q 14 days, until hCG titer is normal EMACO (Etoposide, Metothrexate, Actinomycin, Oncovin), MEA 3 clean-up courses

19. Stage IV patients Initial combination chemotherapy q 14 days 3 clean up courses after the 1st normal titer IF with Brain mets Intrathecalmetothrexate 12.5 mg Steroids or Mannitol For brain decompression