
==== Front
Indian J Nucl Med
Indian J Nucl Med
IJNM
Indian J Nucl Med
Indian Journal of Nuclear Medicine : IJNM : The Official Journal of the Society of Nuclear Medicine, India
0972-3919
0974-0244
Wolters Kluwer - Medknow India

IJNM-39-232
10.4103/ijnm.ijnm_146_23
Interesting Image
White Thyroid Scintigraphy
Zouggari Sara
Bsiss Mohamed Aziz
Matrane Aboubaker
Department of Nuclear Medicine, Mohammed VI University Hospital, Marrakesh, Morocco
Address for correspondence: Dr. Sara Zouggari, Department of Nuclear Medicine, Mohammed VI University Hospital, Marrakesh, Morocco. E-mail: sarazouggari@gmail.com
May-Jun 2024
17 8 2024
39 3 232233
22 12 2023
03 4 2024
12 4 2024
Copyright: © 2024 Indian Journal of Nuclear Medicine
2024
https://creativecommons.org/licenses/by-nc-sa/4.0/ This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.
White thyroid scintigraphy corresponds to an absence or near-absence of radiotracer fixation in the cervical region. After eliminating technical causes, the main etiologies are iodine overload, thyroiditis, and congenital hypothyroidism. We report the case of a 22-day-old newborn with congenital hypothyroidism. As part of the etiological assessment, a cervical ultrasound was performed and showed a normal echostructured thyroid gland with no detectable lesions or vascular anomalies. On the other hand, a Tc 99m thyroid scintigraphy was also performed and revealed a lack of radiotracer uptake in the thyroid area in favor of a white thyroid scintigraphy. Congenital hypothyroidism is the main cause of mental retardation. Thyroid scintigraphy plays an important role in the etiological diagnosis of congenital hypothyroidism. A white thyroid scan and a thyroid in place on cervical ultrasound point to iodine transporter deficiency caused by sodium/iodide symporter gene mutations.

Congenital hypothyroidism
sodium/iodide symporter
white thyroid scintigraphy
==== Body
pmcWe report the case of a 22-day-old newborn with congenital hypothyroidism with thyroid-stimulating hormone (TSH) >60 μIU/mL, and a family history of an older sister being treated for dysthyroidism; however, the mother has no history of any thyroid disease or antithyroid drugs use. First, an iodine interference was ruled out. As part of the etiological assessment, a cervical ultrasound was performed and showed a normal echo-structured thyroid gland with no detectable lesions or vascular anomalies [Figure 1]. On the other hand, a Tc 99m thyroid scintigraphy was also performed and revealed a lack of radiotracer uptake in the thyroid area in favor of a white thyroid scintigraphy. The image also showed an absence or gastric uptake of pertechnetate in regard of the gastric area [Figure 2]. The patient was treated with 50 μg/day of levothyroxine, and 1 month after treatment, the TSH was at 0.311 μIU/mL.

Figure 1 Cervical ultrasound showing a normal echo-structured thyroid gland with no detectable lesions or vascular anomalies

Figure 2 Tc 99m thyroid scintigraphy showing a lack of radiotracer uptake in the thyroid area and an absence or gastric uptake of pertechnetate in regard of the gastric area

Congenital hypothyroidism is the leading cause of preventable mental retardation and growth abnormalities. It may be permanent or transient.[1] Thyroid dysgenesis is the most common etiology of neonatal hypothyroidism, and disorders of hormone synthesis are rarer.[23] Thyroid scintigraphy is currently the most important imaging test that enables the determination of the etiology in the greatest number of cases.[4] A discrepancy between ultrasound and scintigraphy results may point to an anomaly in the gene coding for the iodine transporter known as sodium/iodide symporter.[56] In fact, there is a lack of iodine uptake, and the thyroid scan is, therefore, most frequently “white,” without any contrast, whereas thyroid tissue in place is visible on ultrasound.[78] However, dyshormonogenesis cannot be ruled out, all the more as we have no data of any further investigations carried out on this patient. A syndrome of resistance to TSH can be revealed in a similar form. The phenotypic expressivity of TSH resistance is highly variable going from severe congenital hypothyroidism with thyroid gland of normal/reduced size sometimes with no uptake in the scintigraphy to mild hyperthyrotropinemia (hyperTSH) associated with an apparent euthyroid state.[9] However, the syndrome of resistance to TSH is a rare condition, so the diagnostic workup should exclude other potential causes such as TSH receptor (TSH-R) blocking antibodies that lead to chronic autoimmune hypothyroidism. Similarly, blocking TSH-R antibodies that develop in patients with Graves’ disease during pregnancy may also cause fetal hypothyroidism.[10]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.
==== Refs
1 Van Vliet G Braveman LE Utiger RD Hypothyroidism in infants and children: Congenital hypothyroidism The Thyroid: A Fundamental and Clinical Text New York Lippincott Williams and Wilkins 2004
2 Castanet M Polak M Bonaïti Pellié C Lyonnet S Czernichow P Léger J Nineteen years of national screening for congenital hypothyroidism: Familial cases with thyroid dysgenesis suggest the involvement of genetic factors J Clin Endocrinol Metab 2001 86 2009 14 11344199
3 Cavarzere P Castanet M Polak M Raux Demay MC Cabrol S Carel JC Clinical description of infants with congenital hypothyroidism and iodide organification defects Horm Res 2008 70 240 8 18772598
4 Amellouk S White thyroid scintigraphy and dysthyroidism: About 4 cases Méd Nucl 2021 45 203 33
5 Szinnai G Kosugi S Derrien C Lucidarme N David V Czernichow P Extending the clinical heterogeneity of iodide transport defect (ITD): A novel mutation R124H of the sodium/iodide symporter gene and review of genotype-phenotype correlations in ITD J Clin Endocrinol Metab 2006 91 1199 204 16418213
6 Djemli A Fillion M Belgoudi J Lambert R Delvin EE Schneider W Twenty years later: A reevaluation of the contribution of plasma thyroglobulin to the diagnosis of thyroid dysgenesis in infants with congenital hypothyroidism Clin Biochem 2004 37 818 22 15329322
7 Szinnai G Lacroix L Carré A Guimiot F Talbot M Martinovic J Sodium/iodide symporter (NIS) gene expression is the limiting step for the onset of thyroid function in the human fetus J Clin Endocrinol Metab 2007 92 70 6 17077129
8 Kühnen P Turan S Fröhler S Güran T Abali S Biebermann H Identification of PENDRIN (SLC26A4) mutations in patients with congenital hypothyroidism and “apparent” thyroid dysgenesis J Clin Endocrinol Metab 2014 99 E169 76 24248179
9 Persani L Gelmini G Marelli F Beck Peccoz P Bonomi M Syndromes of resistance to TSH Ann Endocrinol (Paris) 2011 72 60 3 21513912
10 Gaillard S Wondisford FE Thyroid-stimulating hormone and thyroid-stimulating hormone receptor - Clinical Management of Thyroid Disease 2009 81 101
