[Fetus in fetu and acardiac monster: can the similar patterns of these 2 malformations be explained by a common morphogenic mechanism?].

Fetus in fetu and acardiac monster are two unusual malformations (estimated incidences: 1 in 500,000 and 1 in 34,600 deliveries respectively) which present very similar morphological patterns. The authors report two cases of acardiac monster and a case of fetus in fetu which emphasize this fact. These findings suggest that a single morphogenic mechanism leads to the defects observed in these two groups of malformations.