Timing of thyroid ultrasonography in the etiological investigation of congenital hypothyroidism

Abstract

Objectives: To describe the findings of thyroid ultrasonography (T-US), its contribution to diagnose congenital hypothyroidism (CH) and the best time to perform it. Subjects and methods: Forty-four patients with CH were invited to undergo T-US and 41 accepted. Age ranged from 2 months to 45 years; 23 patients were females. All were treated with L-thyroxine; 16 had previously undergone scintigraphy and 30 had previous T-US, which were compared to current ones. Results: At the current T-US, the thyroid gland was not visualized in its normal topography in 10 patients (24.5%); 31 T-US showed topic thyroid, 17 with normal or increased volume due to probable dyshormonogenesis, 13 cases of hypoplasia and one case of left-lobe hemiagenesis. One patient had decreased volume due to central hypothyroidism. Scintigraphy scans performed 3-4 years earlier showed 100% agreement with current results. Comparisons with previous T-US showed concordant results regarding thyroid location, but a decrease in current volume was observed in eight due to the use of L-thyroxine, calling the diagnosis of hypoplasia into question. Conclusions: The role of T-US goes beyond complementing scintigraphy results. It allows inferring the etiology of CH, but it must be performed in the first months of life. An accurate diagnosis of CH will be attained with molecular study and the T-US can guide this early assessment, without therapy withdrawal. Arch Endocrinol Metab. 2017;61(5):432-7

Hemiagenesis of the thyroid gland detected by coincidence—what is the clinical relevance?

“…Surveys in children and adults showed a THA prevalence of 0.016%-0.5% in children and 0.022%-0.25% in adults (Table 1; [1,2,[12][13][14][15][16][17][18][19][20]). However, when children with congenital hypothyroidism were studied with sonography for the underlying pathology, a prevalence of 2.44%-3.7% was found in two surveys [21,22]. In this respect, THA has to be regarded as a relevant cause for congenital hypothyroidism, and sonography in these children should be performed as early as possible to uncover THA or other abnormalities of thyroid development.…”

“…In this context it is thus of interest to what extent hypothyroidism is present in early life. In several studies analyzing the causes of congenital hypothyroidism [12,16,17,21,22,[39][40][41][42], all studies showed that THA can be a cause of congenital hypothyroidism. Maiorana et al [16] found in their survey that children with thyroid hemiagenesis had an average serum TSH significantly higher than that of 18 matched controls (2.8 ± 0.6 mU/l vs. 1.9 ± 0.5 mU/l; P < 0.001), and Cerqueira et al [31] reported that THA was the cause of congenital hypothyroidism in 6% of the cases studied.…”

“…Maiorana et al [16] found in their survey that children with thyroid hemiagenesis had an average serum TSH significantly higher than that of 18 matched controls (2.8 ± 0.6 mU/l vs. 1.9 ± 0.5 mU/l; P < 0.001), and Cerqueira et al [31] reported that THA was the cause of congenital hypothyroidism in 6% of the cases studied. Two other surveys that screened patients with congenital hypothyroidism found THA with a prevalence of 2.33%-3.7% as the cause of congenital hypothyroidism [21,22].…”

“…The different settings were based either on preselection by congenital hypothyroidism, field studies in children and young adults, or results acquired retrospectively in thyroid outpatient wards Author (Ref.) n screened Setting of sonography n THA Comments THA prevalence (%) Borges [ 21 ] 41 Congenital hypothyroidism 1 All patients on L‑thyroxine therapy at time of investigation 2.44 Hashemipour [ 22 ] 437 Congenital hypothyroidism NA All hypothyroid 3.7 Duarte [ 19 ] 964 Field study, children NA – 0.5 Shabana [ 17 ] 2845 Field study, children 6 – 0.2 Korpal-Szczyrska [ 15 ] 4004 Field study, children 2 Both euthyroid 0.05 Hayashida [ 20 ] 4365 Field study, children 2 – 0.05 Maiorana [ 16 ] 24,032 Field study, children 12 9 tested for thyroid function, all euthyroid, but TSH higher than in controls 0.05 Gursoy [ 18 ] 4772/2935 Field study, children/adults 2 All euthyroid 0,025 Suzuki [ 12 ] 299,908 Field study, children and young adults 67 In THA, contralateral thyroid lobe larger compared with normal thyroids 0.016 (male) 0.027 (female) Schneider [ 1 ] NA Thyroid ward, adults …”

“…In this context it is thus of interest to what extent hypothyroidism is present in early life. In several studies analyzing the causes of congenital hypothyroidism [ 12 , 16 , 17 , 21 , 22 , 39 – 42 ], all studies showed that THA can be a cause of congenital hypothyroidism. Maiorana et al.…”