Case Report

Thyrotropin-secreting Pituitary Tumor and Hashimoto's Disease: A Novel Association

Authors: Said B. Iskandar, MD, Edwin Supit, MD, Richard M. Jordan, MD, Alan N. Peiris, MD, PHD

Abstract

A 69-year-old man was referred for elevated thyroid hormone levels. He had no symptoms apart from mild hyperhidrosis and heat intolerance with occasional headaches. Past medical history included a right hemithyroidectomy for a multinodular goiter and Hashimoto's disease. At presentation the patient had a firm, slightly enlarged left thyroid lobe. There were no visual abnormalities, and the rest of the physical findings were unremarkable. Laboratory findings included elevated values of free T4, free T3, total T3, thyrotropin-secreting hormone (TSH), antithyroglobulin, and antimicrosomal antibodies. Normal values were found for cortisol, prolactin, testosterone, follicle-stimulating hormone, luteinizing hormone, &agr;-subunit, and thyroid-stimulating immunoglobulin. Thyroid 123I scan showed an increased 5-hour uptake of 23% and a 24-hour uptake of 53% with a diffuse uniform enlargement of the left side. TSH level did not increase after a thyrotropin-releasing hormone stimulation test. Serum sex hormone binding globulin was elevated. Magnetic resonance imaging of the pituitary revealed a pituitary macroadenoma with suprasellar extension to the optic chiasm. Histologic examination of the adenoma after transsphenoidal hypophysectomy showed cells that stained positive for TSH. TSH-secreting pituitary adenomas account for 1% of functioning pituitary tumors and are an exceedingly rare cause of hyperthyroidism. To our knowledge, this is the first report of pituitary tumor inducing hyperthyroidism in the setting of Hashimoto's disease. There is a possibility that TSH elevation related to Hashimoto's disease might have contributed to the development of a TSH-secreting pituitary adenoma.

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References

1. Gesundheit N, Petrick PA, Nissim M, Dahlberg PA, Doppman JL, Emerson CH, et al. Thyrotropin-secreting pituitary adenomas: Clinical and biochemical heterogeneity—Case reports and follow-up of nine patients. Ann Intern Med 1989; 111: 827–835.
 
2. Beck-Peccoz P, Brucker-Davis F, Persani L, Smallridge RC, Weintraub BD. Thyrotropin-secreting pituitary tumors. Endocr Rev 1996; 17: 610–638.
 
3. Pellegrini I, Barlier A, Gunz G, Figarella-Branger D, Enjalbert A, Grisoli F, et al. Pit-1 gene expression in the human pituitary and pituitary adenomas. J Clin Endocrinol Metab 1994; 79: 189–196.
 
4. Brucker-Davis F, Oldfield EH, Skarulis MC, Doppman JL, Weintraub BD. Thyrotropin-secreting pituitary tumors: diagnostic criteria, thyroid hormone sensitivity, and treatment outcome in 25 patients followed at the National Institutes of Health. J Clin Endocrinol Metab 1999; 84: 476–486.
 
5. Safer JD, Colan SD, Fraser LM, Wondisford FE. A pituitary tumor in a patient with thyroid hormone resistance: A diagnostic dilemma. Thyroid 2001; 11: 281–291.
 
6. Akiyoshi F, Okamura K, Fujikawa M, Sato K, Yoshinari M, Mizokami T, et al. Difficulty in differentiating thyrotropin secreting pituitary microadenoma from pituitary-selective thyroid hormone resistance accompanied by pituitary incidentaloma. Thyroid 1996; 6: 619–625.
 
7. Beck-Peccoz P, Roncoroni R, Mariotti S, Medri G, Marcocci C, Brabant G, et al. Sex hormone-binding globulin measurement in patients with inappropriate secretion of thyrotropin (IST): Evidence against selective pituitary thyroid hormone resistance in nonneoplastic IST. J Clin Endocrinol Metab 1990; 71: 19–25.
 
8. Refetoff S, Weiss RE, Usala SJ. The syndromes of resistance to thyroid hormone. Endocr Rev 1993; 14: 348–399.
 
9. Kocova M, Netkov S, Sukarova-Angelovska E. Pituitary pseudotumor with unusual presentation reversed shortly after the introduction of thyroxin replacement therapy. J Pediatr Endocrinol Metab 2001; 14: 1665–1669.
 
10. Manocha SM, Moulick ND, Shah NS. Primary hypothyroidism presenting as a pituitary gland enlargement with regression following thyroxine therapy. J Assoc Physicians India 2000; 48: 651.
 
11. Alkhani AM, Cusimano M, Kovacs K, Bilbao JM, Horvath E, Singer W. Cytology of pituitary thyrotroph hyperplasia in protracted primary hypothyroidism. Pituitary 1999; 1: 291–295.