Craniopagus parasiticus: successful separation of a 28-week preterm newborn from parasite sibling twin bearing lethal congenital anomalies associated to Cantrell's pentad and sirenomelia-case-based review of the literature.

Craniopagus parasiticus is an infrequent subvariant of this rare form of twin conjointment which may require urgent separation due to the associated malformations of the parasitic twin; therefore, the fact that both siblings are genetically identical may prove as an advantage to use duramater, bone, and soft tissues from the parasitic twin as ideal grafts for covering the resultant defect after the separation has been performed.