08 Jan 2010
Thyroid hemiagenesis (THA) is a rare anomaly present at birth in which one of the thyroid lobes fails to develop. It is usually detected during investigation of other thyroid pathologies, and as imaging techniques improve, more cases of THA are being identified. The literature currently comprises of mainly individual case studies, and there is no consensus on the clinical significance or how THA patients should be managed.
Ruchala et al. have conducted the first systematic analysis of patients with THA using a large cohort comprising 40 subjects with THA who were compared to 80 control subjects with a fully developed thyroid gland. Serum concentrations of thyroid hormones were measured and thyroid ultrasonography and fine-needle aspiration biopsy were performed where possible. Patients with THA were found to have significantly higher concentrations of thyrotropin and free triiodothyronine than controls. A higher incidence of associated functional, morphological and autoimmune thyroid disorders was also observed, and presumed to be due to long-term thyrotropin overstimulation.
This study of THA is the largest conducted to date, and has enabled the authors to conclude that patients diagnosed with thyroid hemiagenesis should be systematically observed and levothyroxine treatment should be provided to those with elevated thyrotropin. Ruchala et al., European Journal of Endocrinology.
