Measurement of serum TSH in the investigation of patients presenting with thyroid enlargement

Abstract

In otherwise euthyroid patients presenting with thyroid enlargement, reduction in serum thyrotrophin (TSH) concentrations measured in a sensitive assay may be a marker of thyroid autonomy and may therefore indicate a benign underlying pathology. We investigated prospectively a cohort of 467 subjects presenting consecutively to our thyroid clinic with nodular or diffuse enlargement of the thyroid. Subjects were divided into those with normal (0.4-5.5 mU/l), low but detectable (0.1-0.39 mU/l) or undetectable (< 0.1 mU/l) serum TSH concentrations. The final pathological diagnosis was defined by fine-needle aspiration cytology and clinical follow-up of at least 2 years or by fine-needle aspiration cytology and histology following surgical treatment. Serum TSH concentrations below normal were found in 75 patients (16.1%), those with low serum TSH results having higher mean free T4 concentrations, were older and were more likely to be female. In those with undetectable serum TSH, no patient had a diagnosis of thyroid neoplasia and in those with low but detectable TSH, thyroid neoplasms were diagnosed in two patients (3.4%). In those with normal serum TSH, 12.0% had a final diagnosis of thyroid neoplasm (p = 0.013). Overall, thyroid malignancy was found in one patient (1.3%) of those with a serum TSH measurement below the normal range and 6.9% of those with normal serum TSH (p < 0.06). Reduction in serum TSH at presentation may identify a group which requires less intensive investigation and follow-up than those without biochemical evidence of thyroid autonomy.

Lack of association between high serum thyroid‐stimulating hormone level and risk of papillary thyroid microcarcinomas

“…11,12,15 In addition, low TSH concentrations below the normal range are associated with a lower risk of thyroid malignancy. 9,12,16,17 In the present study we noted that the risk of malignancy increased in parallel with serum TSH concentrations in patients with thyroid nodules, a finding consistent with previous reports, and the association was restricted to thyroid nodules >1 cm.…”

“…Furthermore, preoperative serum TSH concentrations are higher in patients with more aggressive tumors, suggesting a potential role for TSH in the progression of differentiated thyroid cancer . In addition, low TSH concentrations below the normal range are associated with a lower risk of thyroid malignancy . In the present study we noted that the risk of malignancy increased in parallel with serum TSH concentrations in patients with thyroid nodules, a finding consistent with previous reports, and the association was restricted to thyroid nodules >1 cm.…”

Association between Serum Thyroid Stimulating Hormone Level and Papillary Thyroid Microcarcinoma in Korean Euthyroid Patients

“…In summary, many studies have attempted to confirm the relationship between the development of thyroid cancer and serum TSH level, and most have shown that an elevated TSH level is related to thyroid cancer. The elevated serum TSH level in patients with thyroid abnormalities is associated with thyroid cancer; even within the normal range, there is a higher risk of thyroid cancer among patients with a higher serum TSH level [9][10][11][12]. However, few studies have included only PTMC patients; therefore, the results have been conflicting.…”

“…Some studies reported that an elevated serum TSH level was associated with thyroid cancer [9][10][11][12][13], and one study suggested that the http://www.enm-kes.org serum TSH level was a novel predictor of malignancy [10]. However, another study showed that the serum TSH level was not elevated in papillary thyroid carcinoma [14].…”

Usefulness of serum thyrotropin for risk prediction of differentiated thyroid cancers does not apply to microcarcinomas: results of 1,870 Chinese patients with thyroid nodules

“…Measurement of serum TSH, which is a highly sensitive biochemical test for thyroid dysfunction, is recommended in the initial evaluation of patients presenting with thyroid nodules [9,23]. Encouragingly, several studies discovered an association of serum TSH and thyroid malignancy [12][13][14][15][16][17][24][25][26][27][28][29].…”