Ectopic thyroid tissue in the submandibular region is exceptionally rare. Nevertheless, the treating physician should consider this condition within the differential diagnosis of a submandibular mass.

Case report of ectopic thyroid tissue presenting as a submandibular mass in a patient with hyperthyroidism, together with a review of the English-literature concerning ectopic thyroid tissue.

To our knowledge, this is the first report of ectopic thyroid tissue presenting as a submandibular mass and causing hyperthyroidism. Removal of the submandibular mass resulted in normalisation of thyroid function, and subsequent reduction in the patient's antithyroid medication dosage. Ectopic thyroid tissue should be suspected in any patient with a submandibular mass. Prior to resection of such a lesion, it is essential to ensure that normal, functioning thyroid tissue is present elsewhere. Ectopic thyroid tissue can also present with pathology similar to that affecting the normal thyroid gland.

Cystic lesions related to the upper airway are an unusual cause of infantile stridor. Such a lesion may exert a mass effect, with subsequent airway compromise.

A six-month-old boy was transferred to our unit with a right-sided, level IV neck lump and a three-month history of chronic cough and, latterly, inspiratory stridor. Computed tomography revealed a large, unilocular, cystic, cervicothoracic lesion causing marked compression of the trachea. Airway endoscopy subsequently revealed the larynx to be displaced to the left, with severe external compression of the trachea from just below the subglottic level to immediately above the carina. The mediastinal lesion was excised via an external approach. The histological diagnosis was a bronchogenic cyst.

Bronchogenic cysts are a rare cause of infantile stridor, and should be considered in the differential diagnosis of cystic cervical and mediastinal masses. Surgical excision is the treatment of choice.