The thyroid has many anatomic variations. Zuckerkandl's tubercle (ZT) is the posterior extension of lateral lobes. ZT has a relation with the recurrent laryngeal nerve (RLN). RLN lateral to ZT is an uncommon occurrence. This paper presents two cases of this uncommon situation. A 60-year-old female patient with large multinodular goiter was treated with total thyroidectomy. A 69-year-old male patient with follicular neoplasm was treated with total lobectomy. The inferior thyroid arteries and the recurrent laryngeal nerves were identified with usual lateral approach. A left ZT was found in case 1 and a right ZT in case 2. Distal parts of the RLNs were displaced laterally by enlarged ZTs in both cases. Grade 3 ZTs composed of thyroid tissue were placed between the trachea and the RLNs. The ZT is a common anatomic feature of the thyroid. Close relation of the tubercle with the RLN is an important surgical entity. The enlarged ZT seldom pushes the nerve laterally. The knowledge of the anatomy of ZT and its relation with the RLN including all variations is mandatory for safe thyroid operations.
Surgical procedures on the thyroid gland constitute greater part of endocrine surgery. The thyroid has a lot of embryologic, anatomic, and topographic variations affecting the safety of surgical operations. Therefore, a thyroid surgeon must have intimate knowledge of all structural and anatomic variants of the gland. Emil Zuckerkandl (1849–1910), an Austrian anatomist who described a lateral projection of the thyroid gland, was an early pioneer of clinical anatomy [
In this case report, we present two patients with nodular goiter accompanied with enlarged ZT displacing RLNs laterally.
A 60-year-old female patient with large goiter has been presented to our department with a long-term history of thyroid gland enlargement.
Physical examination, blood chemistry for TSH and FT4, and ultrasound imaging established the diagnosis of euthyroid multinodular goiter. Thyroid ultrasound showed multiple hypoechoic solid nodules in both two lobes and isthmus of the gland. The larger nodules were 32 × 20, 21 × 14, and 22 × 18 mm with irregular margins. The patient was treated with total thyroidectomy.
A 69-year-old man with nodular goiter was evaluated in our department. Thyroid ultrasound showed a 21 × 20 × 23 mm isoechoic nodule in the right lobe and a 6 mm nodule in the left lobe. After fine needle aspiration from dominant nodule, cytological diagnosis was follicular neoplasm. The patient was treated with total “diagnostic” right lobectomy. Final pathologic diagnosis was follicular adenoma.
The inferior thyroid arteries were identified, and isolated, and a loop of silk suture was placed around arteries for traction. With the usual lateral approach, RLNs were identified below the artery and fully isolated in both sides of Case
Enlarged tubercle of Zuckerkandl (Case
A grade 3 Zuckerkandl’s tubercle (Case
After freeing the tubercle of Zuckerkandl and Berry ligament, the RLN returned back to its usual position in trachea-esophageal groove.
The safety of thyroid operations mainly depends on complete knowledge of the embryology, anatomy, and topography of the thyroid gland and related vascular, nervous structures and parathyroid glands including all potential variations. Delbridge [
The relationship between RLN and ZT has been reported in order to prevent surgical injury to the nerve. Identification and preservation of the RLN is a major concern during thyroidectomies. The knowledge of the lobe of Zuckerkandl is essential to perform safe thyroidectomy without injury for the vascular and nervous structures [
The ZT is a poorly known but a common anatomic feature of the thyroid gland. Resection of the enlarged tubercle is indispensable for completeness of thyroidectomy. The close relation of the tubercle with the RLN is an important surgical entity. The enlarged ZT seldom pushes the nerve laterally and superficially. The knowledge of the anatomy of ZT and its relation with the RLN including all the anatomic and topographic variations is mandatory for safe thyroid operations.