Hypothyroidism caused by a nonvisible lingual thyroid.

Abstract

Lingual thyroid is a developmental anomaly caused by failure of migration of the thyroid gland to its normal position in the neck. This anomaly is usually manifested in childhood as hypothyroidism or local symptoms. We present a case of a 32-year-old patient in whom lingual thyroid was diagnosed after complaints of a chronic cough. Thyroid-stimulating hormone levels were significantly elevated. Sonograms of the neck revealed atrophy of both thyroid lobes, with nonhomogeneous consistency and no lymphadenopathy. Technetium-99m scan revealed uptake at the tongue base, with no uptake at the neck or other locations. L-thyroxine treatment was begun, with progressive decrement in thyroid-stimulating hormone levels and cessation of the cough. This case is unique in both the advanced age of the patient and the unusual clinical presentation.