Introduction: The thyroid gland has its embryological origin from the base of the tongue, where it des-cends to the neck. This migratory process can stop early or continue beyond, giving rise to differents cases of ectopic thyroid. The thyroglossal cyst is the most frequent embryological alteration in the neck, and it can develop cancer as a rare complication. Clinical case: A 21 year old patient with a cervical volume increase is diagnosed a thyroglossal cyst. Biopsy identifies papilary cancer in the cyst. It is decided to complete de thyroidectomy, and agenesis of the gland is observed. Due to incomplete biochemical response, a scintigram is performed, wich identifies a retrolingual nodule that is resected. Discussion: The resection of the thyroglossus cyst should be performed according to the description of Sistrunk to avoid recurrence. The natural history of cancer in the thyroglossal cyst is much less known and could have a worst prognosis than usual thyroid cancer. Some groups advocate for the need to complete a thyroidectomy and eventually perform cervical dissections as part of its management. Conclusion: The cancer on a thyroglossal cyst is a rare pathology. There are diferents management approaches that are discussed in the literature. However, an individualized analysis of patients in multidisciplinary expert committees it still the suggested aproach.