True about branchial cyst; is all except

BRANCHIAL CLEFT REMNANTS : • Branchial cleft remnants typically present as a lateral neck mass on a toddler. • Structures of the head and neck are derived from 6 pairs of branchial arches, their intervening clefts and pouches. • Congenital cysts, sinuses, or fistulas result from failure of these structures to regress, persisting in an aberrant location. • All branchial remnants are present at the time of birth; however, they are often not recognized until later in life. • These lesions may present as sinuses, fistulas, or cartilaginous rests in infants. • They occur more commonly as cysts in older children and adolescents. • Clinical presentation may range from a continuous mucoid drainage from a fistula or sinus to the development of a cystic mass that may become infected. • Branchial remnants may also be palpable as cartilaginous lumps or cords corresponding with a fistulous tract. Dermal pits or skin tags may also be evident.