[Sirenomelia as a part of VACTERL association: a study of three cases].

Sirenomelia, characterized by a fusion of lower limb buds, is rare. Moreover, the coexistence of this malformation with a VACTERL sequence is exceptional. We report, here, three new observations associating these two diseases on fetuses from 14 to 26 weeks gestation.

Antenatal diagnosis of a third ventricular mass: fetus in fetu or teratoma?

Background: Fetus in fetu (FIF) is a rare condition in medicine where an aberrant monozygotic twining results in inclusion of a degenerated fetus inside its twin bearer. Whereas FIF is generally defined as a fetiform vertebrate mass, teratoma is considered as a tumor composed of disorganized tissues derived from the three embryological layers. Recent data plead for a common origin and suggest a continuum between FIF and teratoma.