Spontaneous Remission of Hypothyroidism

To the Editor.  Yamamoto and Sakamoto¹ recently described spontaneous remission of severe primary hypothy roidism in a patient with Hashimoto's thyroiditis.¹ I have recently observed a second case of this presumably rare phenomenon.

Report of a Case.  —An 18-year-old woman was first seen at age 13 years at another institution, with complaints of fatigue, cold intolerance, pallor, and swelling in the neck. She consumed a normal American diet. Physical examination confirmed the presence of a large goiter. Laboratory eval uation disclosed a serum free thyroxine index of 0.3 (normal, 4.5 to 12.0) and a serum thyroid-stimulating hormone (TSH) level of 190 μU/mL (normal, < 10 μU/mL); antithyroglobulin antibodies were not de tected, but antithyroid microsomal anti bodies were present in a titer of 1:160. The patient was given levothyroxine sodium, 0.15 mg daily, with resolution of her symp toms. At age 16 years, while receiving levothyroxine, she was clinically euthyroid, with a serum TSH