Endocrine Abstracts

Introduction: Thyroid hemiagenesis (TH) is a rare inborn anomaly of unclear importance. The aim of the study is to describe clinical, hormonal and autoimmunological profile of patients with TH.

Material and methods: The studied group consisted of 20 subjects (4 men), diagnosed of having TH at the age from 15 to 63. Laboratory tests, including measurement of serum concentration of thyroid-stimulating hormone (TSH), free thyroxine (FT₄), free triiodothyronine (FT₃), thyrotropin receptor antibody (TRAb), antithyroid peroxidase antibody (aTPO), antithyroglobulin antibody (aTg) as well as thyroid scintigraphy and ultrasound examination (US), were performed. The data were analyzed with regard to the circumstances and the age of establishing diagnosis, gender, side of agenesis, associated thyroid developmental anomalies, US abnormalities, thyroid volume, hormonal function, concomitant thyroid diseases, administered therapy and the follow-up period.

Results: The left to right sided agenesis ratio was 4:1, with associated isthmus agenesis in 7 (35%). Compensatory enlargement of thyroid lobe was found in 14 cases (70%) and was not correlated to TSH concentration. Thyroid volume was significantly lower in the young (<25 years); P=0.0035. US performed in 17 patients, revealed abnormal echogenity in 13 (76.5%) and focal lesions (nodules and/or cysts) in 8 (47.1%), all benign by fine-needle aspiration biopsy and significantly less often found in younger subjects (<25 years); P=0.044. At diagnosis, 8 patients (40%) were biochemically euthyroid (TSH=2.0±0.38 μIU/ml), 7 (35%)-hypothyroid and 5 (25%)-hyperthyroid. Thyroid autoantibodies were detected in 10 subjects (50%), more frequently among patients >40 years (P=0.069).

Conclusions: The study indicates high prevalence of US abnormalities and thyroid autoimmunological disorders of frequency increasing with age, in subjects presenting TH, probably as a consequence of prolonged TSH overstimulation. Therefore, systematic observation and hormonal treatment, if required, is recommended in all detected cases.