Lingual thyroid presenting as acquired hypothyroidism in the adulthood.

There are numerous reported cases of lingual thyroid with an obvious prevalence in pediatric age. Such ectopic thyroid glands are probably quantitatively deficient and thyroid function may be low or at a low normal level. Apparently, most cases of ectopic thyroid tissue develop congenital hypothyroidism, the so-called cretinism. In this report, we describe a very rare adult male case of lingual thyroid who developed hypothyroidism in adulthood; the anomaly remained undiscovered, being without local common symptoms, and permitted a normal life.