—Pittman et al have described a patient with hyperthyroidism who had several characteristics suggesting the presence of a TSH-secreting pituitary tumor as the cause of his thyrotoxicosis. The features that differ from those seen in Graves' disease include a measurable serum TSH level, an enlarged sella turcica, and the absence of ophthalmopathy. Nevertheless, the presence of thyroid antibodies and demonstration of an empty sella on CT led the authors to favor autoimmune thyroid disease as the cause of the hyperthyroidism in their patient. A brief overview of other reported cases may help place their patient's condition in perspective.Fourteen of 33 patients with TSH-secreting pituitary tumors have had thyroid antibody measurements1 and, in three patients, serum antibodies were detected.2-4 One patient2 had a thyroglobulin antibody titer of 1:25,000, but her serum had no detectable long-acting thyroid stimulator (LATS). Pituitary radiation and thyroidectomy were without effect.