Maternal Klippel–Trenaunay Syndrome with Complete Hydatidiform Mole and Coexistent Fetus: A Case Managed by Surgical Evacuation with Review of the Literature

We assessed 77 twin pregnancies, comprising complete hydatidiform mole (CHM) and healthy co-twin, to ascertain the risks to the mother and baby of continuing the pregnancy, versus termination. 24 women with histologically confirmed CHM and healthy co-twin pregnancies decided to have a termination. 53 women continued with their pregnancies, though two had to have terminations because of severe pre-eclampsia, and 23 spontaneously aborted (<24 weeks' gestation). 28 pregnancies lasted 24 weeks or more, resulting in 20 livebirths. Chemotherapy to eliminate persistent gestational trophoblastic disease (pGTD) was required in three of 19 women (16%; 95% CI 3-39) who terminated their pregnancies in the first trimester, and in 12 of 58 (21%; 95% CI 11-33%) who continued their pregnancies. CHM and healthy co-twin pregnancies have a high risk of spontaneous abortion, but about 40% result in livebirths, without significantly increasing the risk of pGTD.

Partial hydatidiform moles (PMs) rarely require chemotherapy and have never previously been proven to transform into choriocarcinoma, the most malignant form of gestational trophoblastic disease (GTD). Consequently, some have questioned whether women with PMs need human chorionic gonadotropin (hCG) follow-up. Here, we investigate whether PMs can transform into choriocarcinomas. Patients with a PM who developed a subsequent choriocarcinoma were identified from our GTD database. The histology of both PM and ensuing choriocarcinoma was reviewed and flow cytometry used to verify the triploid status of the PMs. To determine whether the choriocarcinoma arose from the PM, DNA from the PM and choriocarcinoma in each patient was compared using microsatellite polymorphisms. Of the 3000 patients with PM, 15 required chemotherapy for persisting GTD. This was identified as choriocarcinoma in three cases. In one patient, the local pathologist could not differentiate between a PM or a hydropic abortion and neither central histological review nor hCG follow-up were obtained. This patient nearly died before the diagnosis of choriocarcinoma was made. Fortunately, the local pathologists correctly diagnosed PM in the two other patients who were then registered for hCG follow-up. Some months later, the hCG was rising and repeat uterine evacuation revealed choriocarcinoma. The PM was confirmed to be triploid in all three cases and genetic analysis showed that the subsequent choriocarcinomas contained identical single maternal and two paternal alleles at several independent loci. Our results show that PMs can transform into choriocarcinoma. All patients with suspected PM should be reviewed centrally and, if confirmed, need hCG follow-up.

A national collaborative study was conducted in Japan to evaluate the clinical course and the sequelae of patients with hydatidiform mole coexistent with twin live fetus (HMTF). Seventy-two cases of HMTF were diagnosed based on gross appearance and histopathological criteria. In 18 cases, the molar parts were cytogenetically confirmed to be of androgenetic origin (complete mole). The overall incidence of persistent trophoblastic tumour (PTT) in patients with HMTF was 30.6%, and it increased to 50.0% in the 18 patients with proven androgenetic complete mole coexistent with twin live fetus (CHMTF). Among these patients, the mean gestational age at termination of pregnancy or delivery in those who developed PTT (n = 9) and those who did not (n = 9) were 20.6 and 19.4 weeks respectively. The incidence of severe maternal complications was significantly higher in patients who subsequently developed PTT (P < 0.05). The rate of subsequent development of PTT in patients with CHMTF was found to be considerably higher than in a previous study of patients with single complete mole (50 and 12.5% respectively). However, since the risk of malignancy is unchanged with advancement of gestational age, continued pregnancy may be allowed in patients with HMTF provided that severe maternal complications are controlled and fetal karyotype and development are normal.