title: Parasitic rachipagus twins; report of two cases.
abstract: BACKGROUND
  Parasitic fetus is a kind of conjoined twin, in which one of the twins is resorbed and some parts of the body can remain attached to the other twin. In the spinal form of parasitic twin--the so-called parasitic rachipagus--an ectopic or accessory limb is attached to the back of a normal baby or only a mass of viable tissue may remain.
  
  
  METHODS
  Here, we report two cases of rachipagus that one had a lower extremity on her back and the other had some tissues similar to genitalia and formed bony structures on his back.
authors.affiliation: Department of Neurosurgery, Shariati Hospital, Tehran University of Medical Science, Tehran, Iran, dr.amini62@gmail.com.
authors.forename: Ami Amini
authors.initials: AA
authors.lastname: Navaei
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Habibi
authors.forename: Ehsan
authors.initials: E
authors.lastname: Moradi
authors.forename: Farideh
authors.initials: F
authors.lastname: Nejat
mesh_terms: D000015:Abnormalities, Multiple / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D013904:Thoracic Vertebrae / Q000002:abnormalities; D014428:Twins, Conjoined / Q000473:pathology* / Q000601:surgery*