Hydatidiform mole with a coexistent fetus is a rare occurrence with an incidence of I per 22,000-100,000 pregnancies. It is associated with persistent gestational trophoblastic tumour. Hence an early and correct diagnosis is imperative to plan subsequent management of such patients. We report a case of a primigravida who presented with vaginal bleeding at early second trimester. Expectant management was carried out for her pregnancy which finally ended in an abortion. The pathology, clinical findings and current management of this rare entity is discussed.
OBJECTIVE: A twin pregnancy consisting of a complete hydatidiform mole with a coexisting normal fetus is extremely rare with an incidence of 1/22,000 to 1/100,000. The incidence of preterm delivery is high and few pregnancies reach near term with a viable fetus.
CASE REPORT: A 34-year-old woman presented at 20 weeks of gestation with increased levels of serum beta human chorionic gonadotropin (beta-HCG) at 4.74 multiples of the median (310277.7 mIU/mL). Ultrasonography showed a hydatidiform mole together with a normal fetus. Fetal karyotyping revealed 46XY. The serum beta-HCG levels were followed up throughout the remainder of the pregnancy. A male infant weighting 2260 g and the molar tissue were delivered at 37 weeks of gestation. The karyotype of the molar tissue showed 46XX and the histopathological report confirmed our diagnosis. At 4 months postpartum, metastatic gestational trophoblastic disease of the lung was diagnosed in the mother by a computed tomography scan due to increased beta-HCG levels. The patient received three unsuccessful cycles of methotrexate and folinate. Another four cycles of chemotherapy consisting of etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine (EMA-CO) were initiated and the beta-HCG levels returned to normal. There was no evidence of recurrence in the subsequent 5 years of regular follow up.
CONCLUSION: A pregnancy with a complete hydatidiform mole and a living cotwin can be a serious threat to the health of both the mother and the fetus. Early diagnosis depends on a combination of detecting an unusually high level of serum beta-HCG and ultrasound examination. We suggest that continuation of the pregnancy may be an acceptable option and that the pregnancy may continue until term if a normal fetal anatomy is assured and maternal complications are under control. Patients require careful postpartum follow up and any recurrent disease should be managed aggressively.
KEYWORDS: EMA-CO; metastatic gestational trophoblastic disease; twin pregnancy with one complete hydatidiform mole
A review of gestational trophoblastic disease diagnosed at the Department of Pathology, University Hospital, Kuala Lumpur from January 1989 to December 1990 using established histological criteria showed 25 complete hydatidiform moles (CHM), 11 partial hydatidiform moles (PHM), 1 invasive mole and 2 choriocarcinoma. The ages of the patients with CHM ranged from 21 to 43 years (mean = 28.5 years) and PHM 20 to 33 years (mean = 27.5 years). The invasive mole occurred in a 42-year-old Malay woman. The two patients with choriocarcinoma were both Chinese and 41 and 46-years old respectively. During the same period, 1,062 non-molar abortions and 13,115 births, inclusive of livebirths and stillbirths were recorded at the University Hospital. The incidence rate of hydatidiform moles was thus estimated to be 1:384 pregnancies. PHM constituted 30% of all molar pregnancies. Hydatidiform moles occurred among the Malays, Chinese and Indians at the rate of 2.43, 2.66 and 3.29 per 1,000 pregnancies respectively. It appears that hydatidiform molar pregnancy has the highest prevalence among the Indians, a finding similar to an earlier Singapore study.
An invasive mole causing uterine perforation is a rare occurrence. We describe below a case with an unusual presentation which was mistaken for an ovarian tumour. The difficulty in diagnosis and the need for a high index of suspicion is highlighted.
22 patients with proven hydatidiform molar pregnancy were subjected to whole lung tomography. By this technique, lung metastases were detected in four patients when plain chest radiographs had shown no secondaries. In a fifth patient additional nodules not observed on the plain radiographs were seen. The usefulness of this procedure as an adjunct to existing methods of following up of patients with metastatic trophoblastic disease is discussed.
A clinicohistological study of acute atherosis in molar pregnancy was undertaken. Maternal decidual vessels in currettage samples of 38 histologically confirmed complete hydatidiform moles were examined histologically for acute atherosis, recognised as fibrinoid necrosis of the smooth muscle wall with a perivascular mononuclear cell infiltrate, with or without lipophages. Acute atherosis was detected in eight of 38 cases, an incidence of 18.4%. All the patients were normotensive. The significance of acute atherosis in molar pregnancy remains to be clarified.
Examination of routinely stained haematoxylin and eosin sections may sometimes prove inadequate in differentiating partial hydatidiform moles (PHM) from complete hydatidiform moles (CHM). While cytogenetic analysis can aid in the distinction, such facilities are not always available. The possibility of using immunohistochemistry to aid in the differentiation was studied. Twenty-five histologically proven CHM and 11 PHM were studied for their patterns of expression of human chorionic gonadotrophin (hCG), human placental lactogen (hPL) and placental alkaline phosphatase (PIAP). All CHM stained diffusely with hCG and focally with both hPL and PIAP irrespective of gestational age. Of PHM, 63.6% were diffusely positive for hCG, 27.3% for hPL and 54.5% for PIAP; the rest were focally positive. The hCG pattern changed from diffuse to focal with increasing gestational age of PHM, while those of hPL and PIAP became increasingly diffuse with gestational age. While these protein expressions may be applied in differentiating late PHM from CHM, it is not useful in first trimester cases. The most helpful application is that focal expression of hCG and diffuse expressions of hPL and PIAP is not seen in CHM, thereby excluding such a diagnosis. PHM, in contrast, can show either diffuse or focal expression of all 3 antigens.