Thyroid Disorders in Patients with Systemic Sclerosis: Biochemical and Sonographic Characteristics. A Prospective Cohort Study.

[BACKGROUND] Patients with systemic sclerosis (SSc) are at increased risk for autoimmune thyroid diseases, but information regarding thyroid nodules and cancer in SSc is scarce. Objectives: To evaluate the thyroid gland in patients with SSc at a single Israeli center.

[METHODS] Thyroid workup was conducted in consecutive SSc patients: thyroid-stimulating hormone (TSH), free thyroxine (fT4), anti-thyroid peroxidase, and anti-thyroglobulin antibodies, as well as thyroid ultrasound and fine needle aspiration (FNA) when appropriate.

[RESULTS] Fifty patients, mean age 51.3 ± 13.5 years (44 women) were evaluated. Ten were previously diagnosed with thyroid disease. Median TSH level was 2.0 (normal range 0.23-4 mIU/l) and median fT4 level was 1.0 (normal range 0.8-2.0 ng/dL). Among the 40 thyroid disorder-naive patients, 3 had subclinical hypothyroidism and 5 had positive anti-thyroid antibodies; 22 (44%) had 1-6 thyroid nodules, which were ≥ 1 cm in 12 (24%). Accordingly, six patients underwent FNA, and five were diagnosed as colloid nodules and one as papillary carcinoma.

[CONCLUSIONS] New cases of clinically significant autoimmune thyroid disease were not detected in our cohort of patients with SSc. Nevertheless, almost half had thyroid nodules. The clinical significance of these findings and their relation to thyroid cancer remains to be determined.