[Problems in thyroid function screening using thyroid stimulating hormone. A case of thyrotoxicosis caused by a thyroid stimulating hormone-secreting pituitary tumor].

UNLABELLED: In a new consensus report from the Danish Society of Internal Medicine a sensitive TSH assay is recommended for screening for thyroid diseases. A patient with thyrotoxicosis, normal serum TSH and a TSH-secreting pituitary adenoma is described. Other reasons for discrepancies between thyroid clinical status and serum TSH are mentioned: Target organ resistance to thyroid hormone, interference in the radioimmunoassay with heterophilic antibodies and insufficient production of TSH because of pituitary disease.

IN CONCLUSION: Screening with TSH is acceptable, but if any discrepancy between TSH values and the clinical picture is found, further tests must be made.