A Case of Thyrotropin (TSH)-Secreting Tumor Complicated by Periodic Paralysis

Abstract

A 27-year-old man had symptoms of hyperthyroidism and periodic paralysis. While hyperthyroid, his serum thyrotropin (TSH) level was inappropriately elevated at 6.4μU/ml. The serum alpha subunit level was also elevated. MR imaging revealed a pituitary tumor and transsphenoidal adenomectomy was performed. Immunocytochemistry with an antibody directed against the beta-subunit of TSH revealed a TSH-secreting tumor.
This is the first case of hyperthyroidism due to a TSH-secreting pituitary tumor complicated by periodic paralysis. This association indicates that thyrotoxicosis may induce paralysis in susceptible persons by a mechanism which is not autoimmune.