Poorly differentiated adenocarcinoma arising from a cervical bronchial cyst presenting as a thyroid mass

Abstract

Bronchogenic cysts are a rare, benign congenital malformation derived from the embryonic foregut and occur most commonly in the mediastinum in close proximity to the thoracic trachea. They are thought to be derived from abnormal sequestrations or budding of the tracheal primordia which are pinched off at the time of fusion of the mesenchymal bars of the sternum, which leaves respiratory tissue outside the thorax.1 Ectopic locations in the neck, though rare, have been described mostly in the pediatric population.2 In adults, cervical bronchial cysts have been reported in the paratracheal, cutaneous, lingual, and supraclavicular areas.2 Malignant change within a bronchial cyst arising in the neck has never been reported. We present the first case of a poorly differentiated adenocarcinoma arising from a cervical bronchial cyst and describe this disease in a patient presenting with a thyroid mass, cervical lymphadenopathy, and a preoperative needle biopsy suggestive of well differentiated thyroid carcinoma.