A male neonate born at term gestation by vaginal delivery to a primigravida mother was admitted at 20 h of life. On examination, he was crying, moving all four limbs, and had normal anthropometry with a head circumference of 35 cm. The anterior fontanel was 4 cm wide in its coronal plane. He had no neurological deficit, and passed urine and meconium once. Over the lumbo-sacral area, a short neck like structure, a single eye and bunch of hair, and no scalp resulting in exposure of underlying brain matter were present excluding any of the facial structure (ear, nose or mouth). This was diagnosed as an incomplete conjoined twin (Fig. 1). The neonate underwent successful removal of the latter and the post-operative course was uneventful.

Incomplete conjoined twin occur when monozygotic twin fail to separate. One of the twins fails to develop into a well-developed individual and remains as a parasite attached to the former.

Fig. 1
figure 1

Clinical picture of one twin showing the lumbo-sacral area over which there is a short neck like structure, a single eye, bunch of hair, and no scalp resulting in exposure of underlying brain matter of the other conjoined twin

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