Background: Conjoined twins may present an extremely wide range of complex congenital malformations. Because of the increasing number of attempts to separate them surgically, profound knowledge is needed of this abnormality spectrum.
Case: Ultrasonographic, radiological (X-ray, computed tomography and magnetic resonance imaging) and pathological findings of gnatho-thoracopagus conjoined twins at 18 weeks of gestation are reported, focusing on clinical topographic correlations.
Conclusions: High-resolution imaging techniques may provide useful information for surgery or autopsy planning of cases with complex congenital malformations.