Congenital Palmar Duplication of the Index Finger: Ventral Polydactyly With Ventral Dimelia

This report describes the case of a 10-month-old boy who presented with a duplicated index finger enveloped by palmar skin on the palmar side of the first web of the left hand. He was healthy without any other abnormalities except the hand anomaly. Surgical resection of the extra finger was performed with triangular flap at 15 months of age. The resected finger was composed of only palmar components: skin without nail or hair; flexor tendons; and digital nerves branching from the median nerve. Histological examination of the specimen demonstrated similar structures on both palmar and dorsal sides, that is, ridged, hairless, and glabrous skin with a high number of epithelial layers and thick corneous stratum and similar shaped tendons inserted into the symmetrical phalanx. This appears to be the first report in literature of an ectopic palmar index finger, a ventral polydactyly with ventral dimelia.