Hello, I can understand your concern. It seems that your son has developed a dermoid cyst between the eyebrows. Dermoid cyst is a cavity under the skin that is filled with dead skin and other cells that usually make the outer layer of the skin. The cyst might be present at the birth but it grows slowly so may have caused swelling after increase in size. The treatment of this swelling includes surgical excision, though the decision of when to do the surgery depend on the child s age, extent of the cyst, child s expected tolerance of the procedure and your own preference. You should consult a pediatric general surgeon for the clinical examination of the swelling and for discussion regarding the diagnosis and course of treatment. I hope this information helps you. Thank you for choosing HealthcareMagic. Take care. Best, Dr. Viraj Shah