A thyrotropin-secreting pituitary adenoma as a cause of thyrotoxic periodic paralysis

J Endocrinol Invest. 1998 Nov;21(10):703-6. doi: 10.1007/BF03350802.


We describe a patient with thyrotoxic periodic paralysis (TPP) caused by a thyrotropin-secreting pituitary adenoma. The diagnosis TPP was based on the combination of episodes of reversible hypokalaemic paralysis, hyperthyroidism and electrophysiological findings. A thyrotropin-secreting pituitary adenoma was diagnosed on the basis of endocrinological function tests and MRI of the pituitary gland. Before transsphenoidal resection of the adenoma, treatment with octreotide restored euthyroidism both clinically and biochemically. Immunocytochemistry of the pituitary adenoma was positive for TSH exclusively. Incubation with octreotide or quinagolide induced decreased TSH and alpha-subunit production by the cultured adenoma cells, in agreement with the pre-operative in vivo data. This paper is the first to describe in vivo and in vitro characteristics of a thyrotropin-secreting pituitary adenoma in a patient presenting with periodic paralysis.

Publication types

  • Case Reports

MeSH terms

  • Adenoma / complications
  • Adenoma / metabolism*
  • Adenoma / therapy
  • Adult
  • Humans
  • Hyperthyroidism / etiology*
  • Hypokalemia / etiology
  • Magnetic Resonance Imaging
  • Male
  • Octreotide / therapeutic use
  • Paralysis / etiology*
  • Pituitary Neoplasms / complications
  • Pituitary Neoplasms / metabolism*
  • Pituitary Neoplasms / therapy
  • Thyrotropin / metabolism*
  • Thyrotropin-Releasing Hormone


  • Thyrotropin-Releasing Hormone
  • Thyrotropin
  • Octreotide