Sirenomelia with an angiomatous lumbosacral myelocystocele in a full-term infant.

Sirenomelia, also known as the mermaid syndrome, is a rare congenital malformation of uncertain etiology. It is characterized by fusion of the lower limbs and commonly associated with severe urogenital and gastrointestinal malformations. In this report, we describe the first case of an infant with sirenomelia and a massive angiomatous lumbosacral myelocystocele.