Parasitic twins: Report of two cases

Abstract

Parasitic twin is a rare malformation, which involves two fetuses attached to each other, whereby one of the pair is viable and develops into a mature embryo (the host twin) called the autosite, while the second twin (parasite) is usually nonviable, but survives on the host twin; the site and extend of their attachment are varied and may be associated with other congenital malformations. Its exact cause is not completely understood. Though, it has been reported in many countries, there is dearth of information on its occurrence in Nigeria. Therefore, we report two cases of parasitic twins seen in our institution. The first case had an extra-limb, scrotal mass projecting from the anterior abdominal wall, which also had an anterior abdominal wall defect below the extra-limb, while the second case had a sacroccoygeal mass which was a duplicate gluteal mass with malformed lower limb, digit with a toe nail projecting from it and an atrophic scrotal skin attached. Both cases had chest, spinal X-rays and abdominal ultrasounds, which excluded any other malformation. They had successful surgical excision of parasites and are being followed-up in the surgical clinic both having appropriate developmental milestones.