Erroneous thyroid diagnosis due to over-the-counter biotin.

Objectives: Biotin is a component of the vitamin B complex used in standard immunoassays to detect serum levels of various hormones and non-hormones, including thyrotropin (TSH) and thyroxine. These assays involve a strong bond between streptavidin and biotin, which serves as an anchor for measured analytes. Large doses of exogenous biotin for the treatment of certain medical conditions have resulted in assay interference, causing TSH to be spuriously lowered.

In Thyroidectomized Thyroid Cancer Patients, False-Positive I-131 Whole Body Scans Are Often Caused by Inflammation Rather Than Thyroid Cancer.

Objective. To show that I-131 false-positive results on whole-body scans (WBSs) after thyroidectomy for thyroid cancer may be a result of inflammation unassociated with the cancer. Methods.

I-131 SPECT/CT elucidates cryptic findings on planar whole-body scans and can reduce needless therapy with I-131 in post-thyroidectomy thyroid cancer patients.

Background: Interpreting I-131 whole-body scans (WBSs) after thyroidectomy for thyroid cancer is not simple. There are scans in which interpretation is speculative because of cryptic findings (CF). Complexity is added in scans that are done a week after an ablative or therapeutic dose of I-131 because not only is I-131-labeled thyroxine (T4) distributed throughout the body, but inorganic I-131 that is derived from the de-iodination of T4 may be also detected.

Radioactivity of blood samples taken from thyroidectomized thyroid carcinoma patients after therapy with (131)I.

Background: Occasionally, blood samples may be required from thyroid cancer patients after they have been given the therapy dose of (131)I, as part of necessary medical management of comorbidities. Thus, in the days after (131)I administration, medical health professionals may be involved in the withdrawal, handling, and manipulation of radioactive blood samples. The purpose of this study was to quantify the amount of radioactivity in blood samples taken from thyroidectomized thyroid carcinoma patients after the administration of therapeutic activities of (131)I.

Evidence and thoughts about thyroid nodules that grow after they have been identified as benign by aspiration cytology.

Coherent management of thyroid nodules that grow after being identified as benign will vary depending on their biology. Some are thyroid-stimulating hormone (TSH) regulated, so a dose of levothyroxine that reduces TSH to the lower limits of normal (subsuppression) may prevent or reverse enlargement; others are controlled by poorly understood mechanisms that must be elucidated before effective medical treatment can be designed; a few are autonomous requiring obliteration, and a very few are "missed" malignancies that should be excised.