Prevalence of associated thyroid pathologies in patients with thyroid hemiagenesis and normally developed thyroid gland
Ewelina Szczepanek, Marek Ruchala, Agata Czarnywojtek & Jerzy Sowinski
Introduction: Thyroid hemiagenesis (TH) is a rare inborn anomaly occurring if one of the thyroid lobes fails to develop. Due to limited literature data and lack of large-cohort casecontrol studies, the clinical significance and management with patients in whom TH was diagnosed, are still a matter of debate. The objective of the study was a complex analysis of a large group of patients with TH in comparison to a control group of subjects born with normal, bilobed thyroid gland in regard to prevalence of associated morphological, functional and autoimmune thyroid pathologies.
Patients and methods: The studied group consisted of 50 patients newly diagnosed with TH. The control group was composed of 100 subjects with bilobate thyroid, matched for age and gender. In the studied patients, serum concentration of TSH, free thyroid hormones (FT4 and FT3), anti-thyroid autoantibodies, calcium, calcitonin and parathormon were measured. Additionally, thyroid ultrasound and scintiscans were performed.
Results: The hormonal production of a single thyroid lobe was, provided no concomitant thyroid disease exists, sufficient to maintain clinical euthyroidism. In patients with TH, in comparison to a control group, higher concentration of TSH and FT3 were observed, while no differences in FT4, calcium, calcitonin and parathormon levels were observed. In patients with TH, hypothyroidism, morphological abnormalities and autoimmune thyroid diseases, in comparison to control group, were more frequently diagnosed (P<0.05). In patients with TH, the incidence of some associated thyroid pathologies was shown to increase with age (P<0.05); along with age also increase in thyroid volume (P=0.0003, r=0.750) parallel to decrease in TSH concentration (P=0.0509, r=− 0.4666) was observed.
Conclusions: Obtained results indicate increased risk of associated thyroid pathologies in patients with TH, therefore a need for systematic observation and introduction of L-thyroxine treatment in case of elevated TSH level.