Clinical usefulness of thyroid ultrasonography in patients with primary hypothyroidism.

Background And Objective: Despite the value of ultrasonography in the detection of chronic thyroiditis (CT) as well as in nodular goitre, it is often only indicated in patients with hypothyroidism if a palpable goitre or a thyroid mass is identified. The objective of the study is to evaluate the clinical usefulness of thyroid ultrasonography in patients with primary hypothyroidism without clinical suspicion of nodular goitre. And more specifically, to analyse its value in the aetiological diagnosis of hypothyroidism, and to evaluate its contribution in the detection and characterisation of coexisting subclinical thyroid nodular disease.

Patients And Method: Prospective cross-sectional observational study of 114 patients with primary hypothyroidism of CT or idiopathic aetiology, without symptoms or cervical palpation suspected of nodular goitre, who underwent a thyroid function test, a serological study of antithyroid antibodies, a thyroid ultrasonound and, when appropriate, a cytological study of the nodules found.

Results: Ultrasonound allowed CT to be recognised as the cause of hypothyroidism in 19% of patients who had a negative serological study, and detected nodules larger than 9mm in 22 patients (16 with antithyroid antibodies). A cytological study was performed in 18 of the cases. Five patients underwent surgery, with carcinoma found in two of them.

Conclusions: Thyroid ultrasound is useful in the aetiological diagnosis of primary hypothyroidism as well as in the detection of a coexisting, unsuspected, but clinically relevant nodular goitre, so this examination should be indicated in the initial study of patients with primary hypothyroidism.