Giant Intrauterine Cystic Malformation of Thumb

A newborn male child, born at 38-week gestation presented with complaint of a giant solitary cystic malformation of right thumb. Mother was non-smoker and non-alcoholic, with no history of any harmful drug or radiation exposure during pregnancy. She was primigravida and antenatal period was uneventful. On examination, a shiny, cystic swelling of 2.5cm x1.5cm x1.5cm was present instead of right thumb which had a nail at one end and the swelling was attached by a skin pedicle with hand (Fig.1A). No other gross congenital malformation was seen. Under regional anaesthesia, the cyst was excised. Histopathological examination revealed straw coloured fluid on cutting the cyst. Microsections showed a cyst lined with stratified squamous epithelium. Microsections examined from thumb showed fibrocartilaginous tissue revealing marked congestion, edema and hemorrhage along with an embedded cartilaginous tissue (Fig. 1B).