No chromosomal imbalances detected by comparative genomic hybridisation in a case of fetal immature teratoma

Abstract

Case report. We present the first application of comparative genomic hybridisation (CGH) in fetal brain tumours in the case of a fetal immature teratoma. The tumour was discovered in a female fetus at 22 weeks gestation after presentation with significant craniomegaly of such degree that the head size measured by sonography was found to correspond to a gestational age of 37 weeks, and the pregnancy was terminated.

Results. Neuropathological examination showed an immature teratoma measuring 1.7×1.6×0.5 cm and containing tissue from all three germinal layers. CGH was successfully performed and, in contrast to earlier results in both cerebral and extracerebral teratomas also investigated with the same technique, it revealed no chromosomal imbalances.

Conclusion. This indicates that mono- or trisomies did not have a role in the pathogenesis in this particular case and that a fetal immature teratoma may contain aberrations smaller than the detection threshold of CGH. However, it remains to be seen in larger cohorts whether fetal teratomas follow a different pathogenetic pathway and may be triggered by different molecular events than teratomas occurring in later life.