Papillary carcinoma in an ectopic thyroid.

Ectopic thyroid tissue can be seen anywhere from the foramen caecum to the lower neck. Most frequently it presents as a thyroglossal duct cyst associated with a normal thyroid gland. Less common is total ectopia, which can occur as a lingual thyroid or occasionally in non-lingual locations. Malignant transformation of such ectopic tissue is extremely uncommon. Only 21 cases of lingual thyroid carcinomas have been reported until 1971. We present, to our knowledge, the first case of a papillary carcinoma in a non-lingual ectopic thyroid in the absence of an orthotopic thyroid.