Two Cases of Enlarged Zuckerkandl's Tubercle of the Thyroid Displacing the Recurrent Laryngeal Nerve Laterally

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

The Rare Coincidence: Nonrecurrent Laryngeal Nerve Pointed by a Zuckerkandl's Tubercle

The safety of thyroid operations mainly depends on complete anatomical knowledge. Anatomical and embryological variations of the inferior laryngeal nerve (ILN), of the thyroid gland itself and unusual relations between ILN and the gland threaten operation security are discussed. The patient with toxic multinodular goiter is treated with total thyroidectomy. During dissection of the right lobe, the right ILN which has nonrecurrent course arising directly from cervical vagus nerve is identified and fully isolated until its laryngeal entry. At the operation, we observe bilateral Zuckerkandl's tubercles (ZTs) as posterior extension of both lateral lobes. The left ILN has usual recurrent course in the trachea-esophageal groove. The right ZT is placed between upper and middle third of the lobe points the nonrecurrent ILN. The coincidence of non-recurrent ILN pointed by a ZT is rare anatomical and embryological feature of this case. Based on anatomical and embryological variations, we suggest identification and full exposure of ILN before attempting excision of adjacent structures, like the ZT which has surgical importance for completeness of thyroidectomy

Case Report Thyroid Hemiagenesis Associated with Hyperthyroidism

Thyroid hemiagenesis (TH), very rare congenital anomaly, is generally asymptomatic. We report two cases of TH with hyperthyroidism. Case One. The patient presented with signs and symptoms of thyrotoxicosis. Physical examination revealed asymmetric nodular goitre at right lobe. Biochemical analysis revealed the diagnosis of hyperthyroidism. Ultrasound showed multinodular hypertrophy in the right lobe and absence of the left lobe. Nuclear scan, confirming absence of the left lobe, showed hot nodules in the right one. The diagnosis was toxic multinodular goitre. Case Two. The thyroid was not palpable in this patient presented with signs and symptoms of thyrotoxicosis. Biochemical analysis revealed the diagnosis of autoimmune thyrotoxicosis. Ultrasound showed mild diffuse hyperplasia of the right lobe and agenesis of the left lobe. Nuclear scan, confirming absence of the left lobe, showed increasing diffuse uptake of radiotracer in the right one. The diagnosis was Graves' disease in this patient. After antithyroid medication, the patients were surgically treated with total excision of the thyroid tissue. TH is sometimes associated with disorders of the thyroid. Hyperthyroidism makes TH cases symptomatic. During evaluation of patients, ultrasound and nuclear scan usually report agenesis of one lobe and establish the diagnosis of TH. The surgical treatment is total removal of hyperactive tissue and total excision of the remaining lobe

Separate thyrothymic thyroid remnant; clinically crucial anatomic variation

Purpose: The anatomical variations of the thyroid gland including separate thyroidal remnant at the thyrothymic area are of significance during thyroid surgery for total thyroidectomy, and for recurrent goitre. In the present study, we aimed to detect the separate rests of thyroidal tissue in the thyrothymic region. Methods: The thyrothymic region was explored for identification, dissection, and excision of separate thyroidal remnants in 134 patients who underwent primary thyroid surgery. In this series, we studied the incidence and anatomical features of the thyrothymic remnant and its relation with other embryologic remnants. Results: Overall, 222 sides of the thyroid were explored in this study. An entirely separate thyrothymic remnant of the thyroid was identified and excised in 8 of 134 patients (6%). Mean size of removed remnants was 36.4 mm (range, 29-45 mm) in diameter. The incidences of pyramidal lobe (PL) and Zuckerkandl's tubercle (ZTI were 71.6% and 59.7%, respectively. The thyrothymic remnant coexisted with PLs in 4 patients. Four patients had all 3 embryologic remnants: thyrothymic remnant, PLs, and ZTs. Conclusion: An entirely separate thyroidal remnant at the thyrothymic area is not a rare variation. The considerably large size of a remnant may threaten the completeness of thyroidectomy and may result in recurrence if it is left behind after thyroid surgery. Awareness, identification, and excision of the separate remnant at the thyrothymic area and the other embryologic remnants are critical for ensuring completeness of thyroidectomy and preventing recurrences.WOS:0005187771000012-s2.0-85082195215PubMed: 3215873

Anatomical and functional identification of the external branch of the superior laryngeal nerve: classification based on morphology and electrophysiological monitoring

Background Motor function of the external branch of superior laryngeal nerve (EBSLN) is vital for voice quality. We studied the rate of EBSLN identification and integrity in the era of intraoperative neuromonitoring (IONM). Methods Anatomic and functional identification of 515 EBSLNs-at-risk was performed under the guidance of IONM that motor integrity was electrophysiologically checked. The functional integrity was assessed with crico-thyroid muscle (CTM) twitches and/or recordable waveform amplitude. We tried to establish the systematic classification of EBSLN identification and integrity. Results Visual, electrophysiological and total identification rates were 64.3%, 31.6% and 95.9%, respectively. We could identify 4.1% of EBSLNs neither anatomically nor electrophysiologically. We recorded CTM twitches alone or both CTM twitches and wave amplitude in 203(39.4%) and 291(56.5%) branches respectively. Identification features of EBSLNs were systematically classified under three main types: Visualized-monitored (1), non-visualized-monitored (2), unidentified (3), and electrophysiological integrity of EBSLNs under two subtypes: CTM twitches alone (a) and CTM twitches and wave amplitude (b). Conclusion Dedicated thyroid surgeon could visually identify EBSLNs. IONM contribution significantly increases the identification rate. Systematic classification of identification and electrophysiological integrity of EBSLNs may increase comprehensive knowledge about its motor function that is crucial for complication-free thyroidectomy.WOS:0006350103000012-s2.0-85103399825PubMed: 3372989

Case Report Two Cases of Enlarged Zuckerkandl's Tubercle of the Thyroid Displacing the Recurrent Laryngeal Nerve Laterally

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

CLINICAL IMPORTANCE OF SOLITARY SOLID NODULE OF THE THYROID IN ENDEMIC GOITER REGION

Context: Endemic area and iodine supplementation may affect the pathogenesis of the nodule which commonly occurs in endemic thyroid enlargement due to iodine deficiency. Aims: To establish pathological changes in solitary solid and larger nodule of the thyroid in endemic area. Setting and Design: Retrospective study in Surgical Department of University Hospital. Methods and Material: We determined 44 surgically treated patients with solitary solid nodule in endemic goiter area in which the population routinely receives iodinated salt. The thyroid nodule was preoperatively evaluated with blood chemistry, ultrasound, nuclear scanning and FNAC. The results of preoperative evaluation, surgical interventions, and histopathological examination were analyzed. Statistical analysis: Student t test and Fisher′s exact test. Results: Twenty (45%;20/44) patients with hot (autonomous) nodule have received the diagnosis of toxic adenoma. Twenty four patients had solitary solid and cold nodule. Total thyroidectomy was performed on two patients with papillary cancer (PTC) diagnosed by FNAC from cold nodules. Forty two patients have been treated with total excision of the lobe including hyper or hypoactive solitary solid nodule. Pathological examination has reported two more cases of PTC and one case of insular cancer arising from cold nodules. Completion thyroidectomy was performed on these 3 patients. Conclusions: Solitary solid and large nodule is a common indication for thyroid surgery in endemic goiter area. High incidence of hyperthyroidism due to single autonomous nodule, and high rate of malignant change (mainly papillary cancer) in solitary hypoactive nodule arises from this series in endemic thyroid enlargement

Pyramidal Lobe of the Thyroid Gland: Surgical Anatomy in Patients Undergoing Total Thyroidectomy

Background. Anatomic variations, the presence of the pyramidal lobe (PL), may impact completeness of thyroidectomy and effect of surgical treatment. Method. This study included 166 patients who underwent total thyroidectomy. The anterior cervical region between the thyroid isthmus and the hyoid bone was dissected during thyroid surgery. The incidence, size, and anatomical features of the PL were established in these patients. Results. The incidence of PL was 65.7%. No gender difference was found for PL incidence. The base of the PL was located at the isthmus in 52.3%, the left lobe in 29.4%, and the right lobe in 18.3% of patients. The mean length of the PL was 22.7 (range, 5–59) mm. The PL was longer than 30 mm in 23% of patients. One-third of the patients with short PL were men whereas women accounted for 80% of patients with long PL. Conclusions. The high incidence indicates that the PL is a common part of the thyroid. The PL generally originates from the isthmus near midline and is of variable length, extending from the isthmus up to the hyoid bone. Considering that the PL is a common structure, the prelaryngeal region should be dissected to achieve the completeness of thyroidectomy