[Sacrococcygeal teratomas in antenatal diagnosis]

The authors report eight cases of antenatal diagnosis of sacro-coccygeal teratoma (SCT) in five girls and three boys in whom the diagnosis was made between the 19th and 34th week of amenorrhea (mean = 27 weeks). The ultrasound pictures taken antenatally of the SCT assist in the discovery of a mass that is usually heterogenous, attached to the distal end of the sacrum, and the discovery is usually made fortuitously or because the height of the uterus is too great. A different series of antenatal diagnoses for SCT have made it possible to work out certain criteria of seriousness to be able to predict intra-uterine death: the presence of anasarca or of hydramnios, the discovery of the lesion before the 30th week of amenorrhoea, the relative weight of the teratoma as against the weight of the fetus being above 50%. We think from our experience that it is important to add the scale of the antenatal growth of the teratoma. A rapid growth of the SCT will lead to a tumour mass which is great as compared to the size of the fetus. Similarly in certain cases the vascular bed will increase in size, and intratumour haemorrhages can occur and give rise to fetal heart failure and also to fetal anaemia, hypoproteinaemia and the appearance of anasarca or of hydramnios. The child dies in utero or immediately after birth because of prematurity from the haemorrhagic state or from cardiac insufficiency. Furthermore accelerated growth of the tumour is nearly always in the immature tumour cells and that means that the child, if it is born alive, should be followed up for a long time because there is a risk of it becoming locally malignant. In practice the monitoring of SCT and the antenatal discovery of the condition should be carried out very seriously in order, in some cases, if it is viable to produce a living child in conditions where the rapid growth of tumour would make it likely that the child would die in utero.