Primary hyperparathyroidism masked by hypothyroidism

Am J Med. 1983 Jan;74(1):144-7. doi: 10.1016/0002-9343(83)91130-0.


In a woman with myxedema and normal total and ionized plasma calcium levels, persistent hypercalcemia developed when she was treated with thyroxine. A parathyroid adenoma was subsequently removed, with return of plasma calcium levels to normal. Hypothyroidism may therefore be a further cause of "masked" primary hyperparathyroidism. The mechanism of masking is likely to have been mediated by hypomagnesemia.

Publication types

  • Case Reports

MeSH terms

  • Adenoma / surgery
  • Aged
  • Diagnosis, Differential
  • Female
  • Humans
  • Hyperparathyroidism / complications
  • Hyperparathyroidism / diagnosis*
  • Hypothyroidism / complications
  • Hypothyroidism / diagnosis*
  • Myxedema / etiology
  • Parathyroid Neoplasms / surgery
  • Thyroxine / administration & dosage


  • Thyroxine