Treatment of a thyrotropinoma with octreotide-LAR in a patient with multiple endocrine neoplasia-1

Objective: To note that a thyrotropin (TSH)-secreting macroadenoma may be part of the multiple endocrine neoplasia-1 (MEN-1) syndrome and to report the use of octreotide-LAR (OCT-LAR) to treat a TSH-secreting macroadenoma in a patient with MEN-1 with previous surgery for hyperparathyroidism and gastrinoma. Methods: We present a patient with a TSH-secreting pituitary macroadenoma and report the results of her endocrine, genetic, radiologic, and nuclear medicine testing and her response to treatment with octreotide (OCT), octreotide-LAR, and estrogen. Results: This patient's TSH-induced hyperthyroidism responded to octreotide for 5 months and octreotide-LAR for more than 11 months. Her hypercalcemia normalized while she was taking estrogen. Her genetic testing is reported to show a genetic defect that is typical of patients with MEN-1. Conclusion: This report describes: (1) The use of octreotide-LAR to treat both a TSH-secreting pituitary tumor and a gastrinoma over 12 months; (2) the importance of including these tumors into the MEN-1 syndrome with its attendant implications; and (3) a genetic defect, typical of patients with MEN-1, associated with this tumor.