Presentation
Asymptomatic child with known hypothyroidism came for his routine control 3 months interval ultrasound
Patient Data
A relatively hypoechoic soft tissue mass lesion is noted inferior to submandibular gland lateral to carotid sheath and thyroid gland, similar to normal thymus echogenicity. The parenchyma had vascularity and the resistive index (RI) measured 0.57.
Case Discussion
Ectopic thymus is an embryological abnormality in children. It can be revealed by a compressive neck mass mistaken for a malignant tumor. Ectopic cervical thymus is seen in ultrasound as a mass of hypoechoic texture and occasionally contain vascularity in color Doppler ultrasound. It can be mistaken for a malignant mass and can go to biopsy unnecessarily, especially intrathyroidal thymus. To avoid unnecessary further examination or biopsy, radiologist must be aware of this situation, especially in the pediatric population.