Ectopic thymus presenting as a submandibular swelling.

Submandibular swellings occur relatively commonly in infants and children. Such swellings may be congenital or acquired. The differential diagnoses generally include common conditions, such as cervical lymphadenopathy, branchial arch anomalies, vascular malformations, inflammatory lesions and, less commonly, neoplasm.1-6 Biopsy or excision is the standard approach taken for most pediatric nonvascular neck masses that fail to resolve after antibiotic therapy.2 Ectopic cervical thymus is a relatively rare occurrence in infants, but it should be considered in the differential diagnosis of a submandibular swelling.