Congenital cystic lymphatic malformations on the extremities are very rare. The patient described in this case study presented with a cutaneous and pedicled macrocystic lymphatic malformation that was eliminated by electrocauterization. A 4-day-old female infant with a congenital cutaneous mass on the dorsal area of her left first metacarpophalangeal joint presented to an outpatient clinic. An electrocautery device was used to cut the pedicle gently with minimal bleeding to avoid mass rupture and to minimize morbidity. A simple wet dressing was applied for 1 week, and the wound subsequently healed completely. Cutaneous macrocystic lymphatic malformations are very rare, especially on the extremities, and no consensus exists on their treatment, which has not been previously described. This report presents this rare case, along with a review of the literature.