Diprosopus: A unique case and review of the literature

Abstract

The pathogenesis is believed to involve duplication of the notochord. Where there are more severe associated anomalies, the prognosis is poor. Partial facial duplication, as in our case, is associated with fewer anomalies, and the prognosis is better. Symmetry and an excess of tissue, rather than deficiency, favor a positive result.

Diprosopus: A Rare Conjoined Twin

“…In 2000 and 2002, two living male infants with partial diprosopus were reported they were considered for surgical correction because of partial form of diprosopus. 8 Diprosopus born in India, where Lali Singh became the most recently known person to have diprosopus like condition and survived for 2 months after birth in 2008. She was the only known individual who survived after birth.…”

Diprosopus tetraophthalmus: CT as a complement to autopsy

“…Diprosopus, representing less than 1% of conjoined twinning, spans a wide spectrum of anomalies that range from minimal facial structure duplication to complete dicephalus [1,3]. A commonly cited proposed aetiology of the diprosopus phenotype is rostral bifurcation or forking of the notochord, which delineates the embryonic axis and induces neurulation.…”

“…A commonly cited proposed aetiology of the diprosopus phenotype is rostral bifurcation or forking of the notochord, which delineates the embryonic axis and induces neurulation. This incomplete division is thought to occur somewhere between 2 and 3 weeks following fertilisation and results in two adjacent vertebral axes, neural plates and neural crest derivatives [1,3]. Diprosopus is found primarily in single pregnancies, but also can be seen in dichorionic twin gestations with a normal co-twin [2], then representing a triplet monochorionic/ dichorionic pregnancy with an incomplete separation of monozygotic twins.…”

“…Duplication of the eyes is always associated with duplication of the nose, but nasal duplication can be isolated [4]. Chromosomal anomalies have not specifically been identified in diprosopus [2,3]. As such, there is no reported increased risk of recurrence.…”

“…The presence of four eyes is designated tetraophthalmus. The incidence of associated central nervous, cardiac and respiratory system anomalies is high [3]. We report a case of an infant characterised as diprosopus tetraophthalmus for whom CT was used as a complement to autopsy to delineate the associated anomalies.…”