Ectopic cervical thymus as a rare cause of pediatric neck mass: the role of ultrasound and MRI in the diagnosis. Case report.

Ectopic cervical thymus (ECT) is an uncommon cause for cervical mass in the pediatric age group. Ultrasound and magnetic resonance imaging findings of the mass (located along the thymic descent pathway along the thymopharyngeal tract and has identical echostructure and signal intensities to the native thymus in the superior mediastinum) would lead to the diagnosis. The diagnosis is confirmed by fine needle aspiration biopsy or histopathology after resection. The management of ECT is a conservative follow up, except in symptomatic cases with tracheal compression and histologically confirmed neoplasia where surgery is indicated. We present the case of ECT presenting as a left upper neck mass in a 12 year old girl.