J Endocr Surg.  2021 Dec;21(4):125-129. 10.16956/jes.2021.21.4.125.

Thyroid Nodule Requiring Thyroidectomy in a Patient with Thyroid Hemiagenesis

• Kim JC
• Kim JJ
• Hwang KT
• Chai YJ

• KMID: 2525969
• DOI: http://doi.org/10.16956/jes.2021.21.4.125

Abstract

Thyroid hemiagenesis (TH) is a rare congenital disorder in which one lobe of the thyroid gland fails to develop. Since most patients experience no clinical symptoms, TH is typically diagnosed incidentally by taking imaging of neck region. In this paper, we report a case of right lobe TH associated with follicular neoplasm. A 65-year-old woman was referred for surgery for a left thyroid nodule, diagnosed as suspicious for follicular neoplasm on fine needle aspiration biopsy (FNAB). In 2012, the patient underwent screening by neck ultrasonography and was incidentally diagnosed with right TH and a left thyroid nodule. The patient had routine follow up for the thyroid nodule and thyroid function tests, and she was diagnosed for subclinical hypothyroidism which did not require medicated until 2015. The patient took thyroid hormone medication for 2 years (2015–2017), until her thyroid hormone levels normalized. In 2021, follow up FNAB was performed on the left thyroid nodule, and cytologic evaluation revealed that the nodule was suspicious for follicular neoplasm. Preoperative computed tomography scan revealed an absence of the right thyroid gland and TH was incidentally diagnosed. Left thyroid lobectomy was performed on this patient, and during operation, neither of right thyroid gland nor isthmus were found. Post operatively, she was prescribed with levothyroxine medication for thyroid hormone replacement. The pathologic report revealed nodular hyperplasia with Hashimoto thyroiditis. Regular follow up and surveillance of patients with TH is recommended for the early diagnosis of other thyroid diseases.

Keyword

Thyroid hemiagenesis; Thyroidectomy; Thyroid nodule