Thyroid ultrasound in patients with Turner syndrome: influence of clinical and auxological parameters.

Objectives: To determine thyroid volume and structure by ultrasound (US) in patients with Turner syndrome (TS) compared to healthy controls; to evaluate the frequency and characteristics of autoimmune thyroid disease (ATD) and its association with clinical and auxological parameters.

Patients: 73 patients and 93 height-matched healthy female controls in the same age range were included in the study.

Results: Thirty-two TS patients (43.8%) presented ATD. They had a larger body mass index (BMI) and presented the 45,X karyotype more frequently than those without. They were older, with a higher prevalence of lymphoedema at birth and pterygium colli without statistical significance. Thyroid volume was 20% larger in the presence of ATD (p=0.037). A dyshomogeneous thyroid structure was observed in all patients with ATD and less frequently in those without (p=0.016). Dyshomogeneity in TS without ATD was also associated with older age (p<0.001), larger BMI (p=0.003) and larger thyroid volume (p=0.006). Six TS patients presented solitary thyroid nodules (5 benign nodules). We observed a significant interaction between diagnosis and height (p=0.035) and age (p=0.047), indicating that both age and height conditioned the observed differences in thyroid volume.

Conclusions: Most TS patients presented ATD with a normal thyroid function or subclinical hypothyroidism, without goiter. Dyshomogeneous thyroid structure was also observed in TS patients without ATD. In TS, the evaluation of thyroid volume according to chronological age does not seem to be efficient because of a link between height and thyroid volume. The prevalence of nodular thyroid disease is similar to that observed in the general population.