Fistulae of the fourth endobranchial pouch.

Eight cases of laterocervical cystic tumor occurring during childhood are described. Three cases presented in the neonatal period as an obstructive tumor. Five cases presented in bigger children as recurrent abcess of the neck. Two of those were initially considered as acute suppurative thyroiditis. Laryngoscopy revealed, in all cases, a fistula originating from the apex of the pyriform sinus. Considering the pharyngeal connections, the anatomical route and the pathological reports, we believe that these cysts are derived from the 4th endobranchial pouch. A review of the literature of the past 10 years reveals only 14 reported cases of laterocervical tumors of similar origin.