Paediatric Radiology

Diagnosis

The location and speckled appearances are typical of a normal thymus gland in the neck, not yet fully descended.

Discussion

The thymus gland is a paired organ that  develops mainly from the ventral wing of the third  pharyngeal pouch on each side. Minor rudimentary 

portions are derived from the fourth pharyngeal  pouch. 

Ectopic cervical thymus is a consequence of migrational defect during embryogenesis. It is seen in infancy and reaches its maximum size upto the age of 2. It usually presents as an asymptomatic neck mass. It does not require therapy or surgical excision, unless there is evidence of airway or esophageal obstruction.