A rapidly growing fetal teratoma

Abstract

In June, 1996, a 25-year-old woman was referred for assessment of a fetus (25 weeks' gestation) with a sacrococcygeal teratoma. The teratoma was first detected on a routine 20-week ultrasound scan. The tumour grew rapidly thereafter to become nearly the size of the fetus. By 25 weeks, polyhydramnios and placentomegaly had developed. Fetal echocardiography showed that a large portion of the fetal cardiac output perfused the teratoma. Placental thickness increased from 40 mm to 60 mm (normal 25 mm) in 1 week, and maternal tachycardia and proteinuria suggested impending maternal mirror syndrome. After maternal general anaesthesia provided fetal anaesthesia and uterine relaxation for open fetal surgery, a low transverse maternal laparotomy and vertical hysterectomy were done.1Adzick MS Harrison MR Fetal surgical therapy.Lancet. 1994; 343: 897-902Abstract PubMed Scopus (131) Google Scholar The fetal rectum was dissected away from the teratoma, which measured 14 cm by 10 cm by 8 cm. A tourniquet was applied to the base of the tumour to constrict the blood flow. Sterile intraoperative ultrasound demonstrated no fetal haemodynamic compromise. The tumour was resected with a 90 mm thick tissue stapler (US Surgical Co, Norwalk, CT, USA) (figure). The fetal sacral wound was closed, amniotic fluid was replaced with warm lactated Ringer's solution and the uterine and laparotomy wounds were closed. Postoperatively, the fetus showed marked skin oedema and ascites and the mother developed vulval oedema; both resolved after maternal fluid restriction and furosemide diuresis. Tocolysis was maintained with magnesium sulphate intravenous infusion and indomethacin rectal suppositories, followed by terbutaline given by subcutaneous pump. By 10 days after fetal surgery, the fetal hydrops and placentomegaly had regressed and the mother was discharged. Pathology of the 400 g teratoma showed a grade III immature teratoma without evidence of malignancy. At 29 weeks' gestation, preterm labour led to the caesarean-section delivery of a 1·33 kg baby girl who required a short period of ventilatory support. The mother recovered uneventfully. The baby underwent a second operation to resect the coccyx and surrounding tissue at 2 months of age; no residual tumour was found. She has met all developmental milestones at 7 months of age. Most sacrococcygeal teratomas diagnosed in neonates have low malignant potential and a good prognosis after resection.2Altman RP Randolph JG Lilly JR Sacrococcygeal teratoma.J Pediatr Surg. 1974; 9: 389-398Summary Full Text PDF PubMed Scopus (565) Google Scholar However, prenatally diagnosed sacrococcygeal teratoma associated with fetal hydrops can be rapidly fatal in utero or lead to polyhydramnios and premature delivery. The high-output cardiac failure is related to a “vascular steal” from the high blood flow through the tumour.3Flake AW Harrison MR Adzick NS Laberge JM Warsof SL Fetal sacrococcygeal teratoma.J Pediatr Surg. 1986; 21: 563-566Summary Full Text PDF PubMed Scopus (143) Google Scholar, 4Langer JC Harrison MR Schmidt KG et al.Fetal hydrops and death from sacrococcygeal teratoma: rationale for fetal surgery.Am J Obstet Gymecol. 1989; 160: 1145-1150Summary Full Text PDF PubMed Scopus (138) Google Scholar, 5Flake AW Fetal sacrococcygeal teratoma.Sem Pediatr Surg. 1993; 2: 113-120PubMed Google Scholar Fetal hydrops and placentomegaly may also jeopardise maternal health through the maternal mirror syndrome, in which the maternal condition begins to “mirror” that of the sick fetus. In this case we considered that resection of the tumour in utero might prevent the maternal mirror syndrome and fetal death. Previous attempts at resection of sacrococcygeal teratomas have failed because of advanced fetal hydrops and placentomegaly. This case demonstrates that resection earlier in the disease course can have a successful outcome.