[Lingual thyroid and intra-lingual thyroglossal cyst. Apropos of 2 cases].
Lingual thyroid and intra lingual thyro-glossal cyst are two benign tumours of similar embryological pathogenesis respectively with the arrest in the ectopic position of the thyroid gland during its downward migration and from abnormal persistence of the thyro-glossal tract for the cyst. The occurrence of lingual thyroid is rare 1/100,000 patients and outnumbers the incidence of intra-lingual cyst which represents an estimated 2.1% of the thyro-glossal cysts or fistulas. Both lesions are a rare cause of dysphagia and dyspnoea due to oropharyngeal obstruction, and radionuclide scintigraphy combined with CT and/or MRI will establish the diagnosis. Surgical pharyngotomy with an infra-hyoid approach provides excellent access to the lesions and complete removal of the tumours.