[Serum thyroglobulin levels in patients with thyroid tumor].

Serum thyroglobulin (Tg) levels were measured in 15 normal volunteers, 69 patients with differentiated thyroid carcinoma, 22 with adenoma, 45 with adenomatous goiter, 5 with functioning adenoma and 24 with Graves' disease, utilizing a double antibody radioimmunoassay technique. Serum Tg levels in the normal volunteers were found to be less than 30 ng/ml as determined from their mean value, i.e., 16.9 +/- 13.4 ng/ml (mean + 2SD), whereas serum Tg in the patients with various thyroid disorders showed significantly elevated (P less than 0.01). Serum Tg of patients with differentiated thyroid carcinoma without distant metastasis was 71 +/- 7 ng/ml (mean +/- SE), that in adenoma 124 +/- 22 ng/ml, that in adenomatous goiter 147 +/- 19 ng/ml, that in functioning adenoma 120 +/- 41 ng/ml, and that in Basedow disease 122 +/- 22 ng/ml. Furthermore, it appears that Tg concentration in serum is correlated with the size of the nodules in differentiated thyroid carcinoma (P less than 0.01) and benign nodules (P less than 0.05). Present results suggest that thyroid tumor also release Tg into serum in addition to Tg stored in the normal tissue. Furthermore, the level of circulating Tg in patient is not correlated to the level of serum TSH. In treated differentiated thyroid carcinoma, serum Tg levels were markedly reduced (21 +/- 2 ng/ml) in patients with no evidence of either recurrences or metastases, but significantly elevated in those with recurrences and/or metastases (257 +/- 109 ng/ml). Therefore, serum Tg measurements in the follow-up of patients treated for differentiated thyroid carcinoma are useful in the search for recurrences or metastases.