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| CASE REPORT |
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| Year : 2013 | Volume
: 10
| Issue : 2 | Page : 78-79 |
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Recurrent thyrotoxicosis due to hyperfunction of multiple ectopic thyroid tissue and residual thyroid lobes 15 years after thyroidectomy: Evaluation using technetium scanning and hybrid single-photon emission computed tomography/CT
Chidambaram N. B. Harisankar1, Govindababu R Preethi2
1 Department of Nuclear Medicine and Therapy, Amala Institute of Medical Sciences, Amalanagar, Thrissur, Kerala, India
2 Department of Radiodiagnosis, Amala Institute of Medical Sciences, Amalanagar, Thrissur, Kerala, India
| Date of Web Publication | 16-Apr-2013 |
Correspondence Address:
Chidambaram N. B. Harisankar
Department of Nuclear Medicine, Amala Institute of Medical Sciences, Amalanagar, Thrissur, Kerala
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0973-0354.110592
Ectopic thyroid tissue (ETT) refers to all cases in which the thyroid gland is present at a location other than its usual site. Hyperthyroidism in ETT is very rare with only a few cases reported in literature. We report a 48-year-old female, a case of relapse of hyperthyroidism 15 years after thyroidectomy. Technetium scanning with hybrid single-photon emission computed tomography (SPECT)/CT showed increased trapping function in residual orthotopic thyroid lobes. Increased trapping function was also noted in two other ectopic sites. The patient was treated with radioiodine. Keywords: Ectopic thyroid, hyperthyroidism, multiple ectopic, radioiodine ablation
How to cite this article:
Harisankar CN, Preethi GR. Recurrent thyrotoxicosis due to hyperfunction of multiple ectopic thyroid tissue and residual thyroid lobes 15 years after thyroidectomy: Evaluation using technetium scanning and hybrid single-photon emission computed tomography/CT. Thyroid Res Pract 2013;10:78-9 |
How to cite this URL:
Harisankar CN, Preethi GR. Recurrent thyrotoxicosis due to hyperfunction of multiple ectopic thyroid tissue and residual thyroid lobes 15 years after thyroidectomy: Evaluation using technetium scanning and hybrid single-photon emission computed tomography/CT. Thyroid Res Pract [serial online] 2013 [cited 2022 Dec 5];10:78-9. Available from: https://www.thetrp.net/text.asp?2013/10/2/78/110592 |
| Introduction | |  |
The thyroid gland develops from the foregut. At about 4 weeks of gestational age, an evagination appears between the first and second pharyngeal pouches which lengthens to form a tube, and descends inferiorly and anteriorly to pass anterior to the hyoid bone. It then loops round and behind the hyoid before continuing its descent in the neck to finally form two lateral buds; these will become the lateral lobes. [1] Most ectopic thyroid glands are asymptomatic. It is unusual for multiple ectopic thyroid tissues (ETTs) to be present simultaneously. Hyperthyroidism in ETT is extremely rare. [2],[3],[4],[5]
| Case Report | | |
A 48-year-old female presented with palpitations, breathlessness, and tremors. She had history of thyroid surgery before 15 years for hyperthyroidism, the details of which are not known. Presently, she had a globular swelling in the upper part of the neck, which was gradually enlarging in size over the past 18 months. The swelling, on clinical examination, moved with deglutition and protrusion of the tongue. A thyroidectomy scar was noted and there was fullness in the suprasternal region. On clinical and biochemical examination, she was overtly hyperthyroid. Ultrasonogram of the neck showed residual right and left lobes of thyroid gland in the neck with hypoechoic and granular parenchyma. The residual right lobe measured 4.0 × 2.0 × 2.5 cm and the left lobe measured 2.0 × 0.9 × 0.9 cm. Two lesions with similar morphology separate from the residual thyroid lobes were also noted in the infrahyoid region (size: 2.6 × 2.3 × 1.4 cm) and suprasternal region (size: 3.4 × 1.6 cm), respectively. Technetium scanning showed multiple sites of intense tracer uptake in the neck [Figure 1]. Fine needle aspiration cytology from the subhyoid swelling and right lobe of thyroid showed thyroid tissue without any evidence of malignancy. Patient was treated with 555 MBq (15 mCi) of iodine-131 and was on regular follow-up. | Figure 1: (a) Planar technetium thyroid scan done after intravenous injection of 99mTc-NaTcO4 shows intense tracer uptake in multiple sites in the neck. The technetium uptake in the lesions was significantly increased. On hybrid SPECT/CT, the lesions were localized to the clinically palpable swelling in (b) thyroid remnants, (c) the infrahyoid region, (d) a soft tissue lesion in suprasternal region. Sagittal image (e) shows the location of the functioning thyroid tissues
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| Discussion | | |
The original position of thyroid gland is marked by the foramen cecum at the junction of anterior two-thirds and posterior one-third of the tongue. The pathway from the pharynx to the anterior neck is marked by the thyroglossal duct. [1] ETT may be located anywhere in the path of descent of the normal thyroid gland and may be imaged using fusion imaging. Multiple thyroid ectopia are very rare. [1],[6],[7] Hyperthyroidism in ETT is extremely rare. [2],[3],[4],[5] Recurrence of hyperthyroidism after thyroidectomy due to stimulation of ectopic thyroid has been previously described. [8],[9] It is possible that the circulating thyroid stimulating immunoglobulin can influence the thyroid cells present in ectopic locations. [9] Under the influence of these antibodies, the ETT hypertrophy and cause hyperthyroidism.
Another differential diagnosis of such presentation is functioning thyroid metastases causing hyperthyroidism. [10] Functioning thyroid cancer metastases are extremely rare and are usually well-differentiated follicular carcinomas. [10]
| References | | |
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| 9. | Basili G, Andreini R, Romano N, Lorenzetti L, Monzani F, Naccarato G, et al. Recurrence of Graves' disease in thyroglossal duct remnants: Relapse after total thyroidectomy. Thyroid 2009;19:1427-30.
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| 10. | Haq M, Hyer S, Flux G, Cook G, Harmer C. Differentiated thyroid cancer presenting with thyrotoxicosis due to functioning metastases. Br J Radiol 2007;80:e38-43.
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[Figure 1]
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