Unusual presentation of heteropagus attached to the thorax.

The endoparasitic twin is the most common form of asymmetric fetal duplication (heteropagus). A 2-month-old girl who had a parasitic right lower limb with axial skeleton, vertebral column, uterus, fallopian tube, ovary, and bladder implanted in the sternum region is described as another example of exoparasitic twin, the uncommon form of heteropagus. Unusually, dextrocardia was found in the autosite. This report emphasizes the even progression between the endoparasitic and exoparasitic forms of heteropagus.