External and computed tomography analysis of a strophocephalic lamb

The Museum of Anatomy and Embryology Louis Deroubaix attached to the Laboratory of Anatomy, Biomecanics and Organogenesis, ULB, Brussels, possesses in its liquid collections a cephalic extremity of a lamb suffering from strophocephaly. The origins have not been determined. The trunk and the limbs are resected.

The piece has been studied and photographed. A volumic computed tomography acquisition has been performed with a Siemens Volume Zoom. For pedagogic and museological purposes, surface reconstructions and 3D printing have been obtained.

An otocephaly is observed. Both ears are located in place of the oral cavity. The mandible is welded to the braincase. The eyeballs are close together (synophtalmia) which confirms the presence of a cyclotocephaly. They are surmounted by a rudimentary snout rather than a proboscis. The presence of this muzzle allows the anomaly to be classified as a strophocephaly, a malformation already described in sheeps. CT slices of the brain show a semi-lobar holoprosencephaly with incomplete division of the cerebral hemispheres and ventricules.

The CT examination allows the facial anomalies to be allocated to a holoprosencephaly. The singularity of this case, compared to the human cyclotocephalies, is the presence of a differentiated muzzle rather than a simple proboscis. The holoprosencephaly is uncomplete. Such anomalies have been associated with an entire absence of cerebral differentiation but with a complete absence of the muzzle. The tridimensional printing represents an interesting educational tool easily transportable in contrast to the original specimen.