The thyroid is an endocrine gland composed of two lobes connected by the isthmus tissue. Thyroid isthmus agenesisis a rare condition, and only a few cases have been reported in the literature. Here, we discuss the case of a 56-yearoldfemale patient in whom agenesis of the thyroid isthmus was discovered incidentally during surgery for a multinodulargoitre. When agenesis of the isthmus is found, associated thyroid lobe agenesis and the presence of ectopicthyroid tissue must be considered. In addition, associated autoimmune thyroid nodule, thyroiditis, primary thyroidcarcinoma, metastasis, and amyloidosis must be considered in the differential diagnosis. Preoperative awarenessof potential agenesis of the isthmus and its associated thyroid anomalies in patients with planned thyroid surgerywill significantly contribute to safety during surgical procedures and result in fewer surgery-related complications.
Dixit D, Shilpa MB, Harsh MP, Ravishankar MV. Agenesis of isthmus of thyroid gland in adult human cadavers: a case series. Cases J 2009; 2: 6640. [CrossRef]
Taty-Anna K, Farihah HS, Norzana AG, Farida H, Das S. Absence of the isthmus of the thyroid gland: anatomical and clinical considerations. Clin Ter 2012; 163: 503-504.
Kumar GP, Satyanarayana N, Vishwakarma N, Guha R, Dutta AK, Sunitha P. Agenesis of isthmus of thyroid gland, its embryological basis and clinical significance--a case report. Nepal Med Coll J 2010; 12: 272-274.
Ozkan OF, Asık M, Toman H, Ozkul F, Cıkman O, Karaayvaz M. Agenesis of isthmus of the thyroid gland in a patient with gravesbasedow disease and a solitary nodule. Case Rep Surg 2013: 608481. [CrossRef]
Vayisoglu Y, Ozcan C, Gen R, Eti CM, Sut H, Gorur K. Thyroid isthmus agenesis associated with thyroid papillary carcinoma. J Craniofac Surg 2013; 24: e428-429. [CrossRef]
Ranade AV, Rai R, Pai MM, Nayak SR, Prakash, Krisnamurthy A, et al. Anatomical variation of the thyroid gland: possible surgical implications. Singapore Med J 2008; 49: 831-834.
Sankar KD, Bhanu PS, Bapuji P. Agenesis of isthmus of thyroid gland with embryological and clinical basis. Narayana Medical Journal 2012; 1: 32-34.
Gangbo F, Lacombe D, Alberti EM, Taine L, Saura R, Carles DN. Trisomy 22 with thyroid isthmus agenesis and absent gall bladder. Genetic Counseling 2004; 15: 311-315.
Pastor VJF, Gil VJA, De Paz Fernández FJ, Cachorro MB. Agenesis of the thyroid isthmus. Eur J Anat 2006; 10: 83-84.