Anti-thyroid antibodies as a predictor of thyroid cancer.

BACKGROUND: Recent literature has suggested an association between autoimmune thyroiditis and papillary thyroid cancer. The aims of this study were to evaluate if positive thyroid antibodies are associated with thyroid carcinoma and to examine the role of thyroid antibodies in the management of thyroid nodules. METHODS: This is a database study of all patients undergoing thyroidectomy with recorded preoperative thyroid antibodies (autoantibodies to thyroglobulin and/or thyroid peroxidase) levels from 2010 to 2012. We analysed preoperative thyroid antibody levels, fine needle aspiration cytology (FNAC) results, type of thyroid surgery and final histopathology. RESULTS: There were 960 patients who underwent thyroidectomy with recorded preoperative thyroid antibodies. Of 960 patients, 784 had preoperative FNAC of thyroid nodules. Final histopathology showed 758 benign and 202 malignant cases. As expected, there was a strong association between raised thyroid antibodies and lymphocytic thyroiditis on histology (P = 0.0001) (two-sided probability). Overall, positive thyroid antibodies were not found to be a predictor of thyroid carcinoma (P = 0.161) (two-sided probability). However, in patients with benign FNAC, positive thyroid antibodies increased the risk of thyroid malignancy (odds ratio 2.16; 95% confidence interval 1.11 to 4.21, P = 0.027) (two-sided probability). CONCLUSION: Patients with positive thyroid antibodies have a greater risk of malignancy in those with benign FNAC. We recommend routine thyroid antibody assessment in addition to FNAC as part of the assessment of thyroid nodules.

Differential recurrent laryngeal nerve palsy rates after thyroidectomy.

INTRODUCTION: Recurrent laryngeal nerve (RLN) palsy is a devastating complication of thyroidectomy. Although neurapraxia is thought to be the most common cause, the underlying mechanisms are poorly understood. The objectives of this study were to examine the differential palsy rates between the left and right RLNs, and the role of intraoperative nerve swelling as a risk factor of postoperative palsy. METHODS: Thyroidectomy data were collected, including demographics, change in RLN diameter, and RLN electromyographic (EMG) reading. Left and right RLNs, as well as bilateral and unilateral subgroup analyses were performed. RESULTS: A total of 5,334 RLNs were at risk in 3,408 thyroidectomies in this study. The overall RLN palsy rate was 1.5%, greater on the right side than the left for bilateral cases (P = .025), and greater on the left side than the right for unilateral cases (P = .007). In a subgroup of 519 RLNs, the diameter and EMG amplitude were measured. The RLN diameter increased by approximately 1.5-fold (P < .001), and corresponded to increased EMG amplitude (P = .01) during the procedure. The diameter of the right RLN was larger than the left RLN, both at the beginning and end of the dissection (P = .001). CONCLUSION: The right-left differential rates of post-thyroidectomy RLN palsy seemed to be due in part to differential RLN diameters, with stretch having a more deleterious effect on RLNs with a smaller diameter; also, edema as a result of stretch might be an underlying mechanism for postoperative neurapraxia and palsy. Thyroid surgeons should be aware of the different vulnerabilities of each RLN and develop practices to avoid iatrogenic injury.

Fine-needle aspiration of the thyroid: correlating suspicious cytology results with histological outcomes.

PURPOSE: Fine-needle aspiration cytology (FNAC) assists the diagnosis of thyroid malignancy. A 'suspicious for malignancy' on FNAC creates a management dilemma. The aims of this study were to investigate the malignancy rate for patients with suspicious cytology, and to describe a management approach for those with a suspicious result. METHODOLOGY: A retrospective review of prospectively collected data in an endocrine surgery database was undertaken. Patients undergoing thyroidectomy with preoperative FNAC from 1992 to 2012 were analysed. RESULTS: Preoperative FNAC was undertaken in 2,692 patients, and the FNAC result was 'suspicious for malignancy' in 94 (3.5 %) patients. Of these, 53 (56.4 %) were malignant, with the majority 44 (83.0 %) being papillary thyroid cancer. 48 patients went straight to total thyroidectomy, 40 patients had an initial diagnostic hemithyroidectomy, and 1 patient had a diagnostic isthmusectomy. 5 patients required reoperative total thyroidectomy as an initial procedure. Of the 94 suspicious cases, 55 were reported by an unknown, presumably non-expert, thyroid cytopathologist. 38 of these cases were available for review and re-reporting by an experienced cytopathologist. On review, 28 (73.7 %) were reclassified as cytologically malignant, and all of these were confirmed as malignant on subsequent histopathology. CONCLUSIONS: Suspicious cytology has a high risk of malignancy. Expert thyroid cytopathology can improve diagnostic accuracy and a preoperative malignant diagnosis should be pursued to enable one-stage surgery where possible.

Well-differentiated thyroid carcinomas: management of the central lymph node compartment and emerging biochemical markers.

Well-differentiated thyroid cancers (WDTCs) are generally indolent cancers that are associated with a low mortality. Although the incidence of these tumors is increasing, there has not been an associated increase in the mortality rates. As we gain a greater understanding and more experience with these good prognosis cancers, the way in which we treat these tumors is evolving. The definition of persistent or recurrent disease has seen a shift from being a clinical and/or radiological diagnosis to now one based on a biochemical blood marker, thyroglobulin. Central lymph node metastases are a very common problem in WDTC, being present in up to 90% of patients. The optimal surgical management of the central lymph node compartment remains a hotly debated topic. This paper identifies these controversies and presents available data surrounding these issues. Biochemical tumor markers are gaining wider use in practice and in time hopefully provide more specific information with which surgical decision-making can be based. A summary of the clinically available markers is presented.

Surgery in the setting of Hashimoto's thyroiditis.

BACKGROUND: Hashimoto's thyroiditis (HT) is a chronic autoimmune thyroiditis typically resulting in hypothyroidism. In itself, HT is not an indication for surgery but the co-existence of thyroid nodular disease creates diagnostic and management difficulties. Indications for thyroidectomy include risk of malignancy and pressure symptoms. While fine needle aspirate cytology is effective in the diagnosis of thyroid lesions, in HT there is increased diagnostic uncertainty. This study aimed to document the results of cytology and the rate of malignancy in HT. METHODS: Data were analysed for the period 1996­2009. All patients who underwent thyroidectomy and had a formal histological diagnosis of HT were included and compared with a control population who underwent thyroidectomy but did not have HT. In both groups, patient demographics, clinical parameters, cytology findings, operative procedure and final histology were reviewed. RESULTS: One hundred and twelve patients had histologically proven HT, with a significant female preponderance compared with controls (P = 0.002). There were no significant differences between cases and controls for type of procedure or preoperative examination findings. Incidence of hypothyroidism was increased: 17 patients (15.2% versus 1.6%; P < 0.0001), whereas thyrotoxicosis was decreased: four patients (3.6% versus 14.4%; P = 0.002). There was an increased incidence of follicular/indeterminate cytology (35.7% versus 22.1%; P = 0.001). While there was an increased false negative rate in HT, this failed to achieve statistical significance (8.8% versus 2.5%; P = 0.09). Malignancy rates were more prevalent in the setting of HT (23.2% versus 11.4%; P < 0.001). CONCLUSIONS: Given the increased rate of associated malignancy and increased diagnostic uncertainty in patients with HT, we recommend routine preoperative thyroid antibody measurement.

Gastrinomas: a historical perspective.

The journey of gastrinomas had its beginnings in 1955 when Zollinger and Ellison published their seminal paper (Zollinger and Ellison, Ann Surg 1955; 142: 709-723). The evolution of the diagnosis and management of this syndrome has paralleled many important advances in medicine, including the development of various diagnostic tools to the major impact of medical treatment on the management of an inherently surgical pathology. There are numerous excellent review articles on the most current developments and treatment options of gastrinomas available in the literature today. The purpose of this paper is to present a historical perspective on this most fascinating condition. This article will illustrate the way in which the discovery of gastrinomas evolved and how its management has developed with it. The evolution of the surgical treatment of gastrinomas has evolved over the last 50 years.

The motor fibers of the recurrent laryngeal nerve are located in the anterior extralaryngeal branch.

OBJECTIVE: This study aimed to establish the prevalence of extralaryngeal bifurcation of the recurrent laryngeal nerve (RLN) and investigate the location of the motor fibers to the intrinsic muscles of the larynx within the branches of the RLN. SUMMARY OF BACKGROUND DATA: Recognition of extralaryngeal branching of the RLN is important, because inadvertent division of a branch may lead to significant vocal cord palsy despite the operator believing the nerve was preserved. METHODS: Prospective operative data on branching of the RLN were collected in 579 patients undergoing thyroidectomy or open parathyroidectomy over a 3 year period and nerve integrity monitoring was utilized to document the position of the motor fibers of the last 176 RLNs. Adduction of the vocal cords was detected by the electromyography-endotracheal tube and abduction by finger palpation of muscle contraction in the posterior cricoarytenoid. RESULTS: A total of 838 RLN were studied (right--432, left--406). Bifurcations occurred on the right in 111 (25.7%) and left 93 (22.9%). Bilateral bifurcation occurred in 23 (8.9%) of bilaterally dissected nerves. Overall 176 RLNs in 118 patients were assessed by the nerve integrity monitoring. Of these 41 (23.3%) were bifid RLN. In all 41 (100%) cases of bifid RLN, motor fibers for both adduction and abduction of the vocal cords were located exclusively in the anterior branches of RLN, and none in the posterior branches. CONCLUSION: Extralaryngeal bifurcation of RLN is a common anatomical variant. The motor fibers of RLN are located in the anterior branch, for both adduction and abduction. Great care is therefore required following the presumed identification of the RLN to ensure there is no unidentified anterior branch.

Management of the solitary thyroid nodule.

Thyroid nodules are common, with up to 8% of the adult population having palpable nodules. With the use of ultrasound, up to 10 times more nodules are likely to be detected. Increasing numbers of nodules are being detected serendipitously because of the rising use of imaging to investigate unrelated conditions. The primary aim in investigating a thyroid nodule is to exclude the possibility of malignancy, which occurs in about 5% of nodules. This begins with a thorough history, including previous exposure to radiation and any family history of thyroid cancer or other endocrine diseases. Clinical examination of the neck should focus on the thyroid nodule and the gland itself, but also the presence of any cervical lymphadenopathy. Biochemical assessment of the thyroid needs to be followed by thyroid ultrasound, which may demonstrate features that are associated with a higher chance of the nodule being malignant. Fine-needle aspiration biopsy is crucial in the investigation of a thyroid nodule. It provides highly accurate cytologic information about the nodule from which a definitive management plan can be formulated. The challenge remains in the management of nodules that fall under the "indeterminate" category. These may be subject to more surgical intervention than is required because histological examination is the only way in which a malignancy can be excluded. Surgery followed by radioactive iodine ablation is the mainstay of treatment for differentiated thyroid cancers, and the majority of patients can expect high cure rates.

Development of a parathyroid database in Melbourne and review of the last 50 cases.

BACKGROUND: Minimally invasive parathyroidectomy (MIP) is only possible if preoperative localization studies accurately identify the abnormal parathyroid tissue. The aim of the present paper was to evaluate the accuracy of these studies in our geographical region and the consequences on MIP. METHODS: A Filemaker Pro database was designed and a retrospective analysis was carried out on the last 50 parathyroidectomies. RESULTS: There were a total of 49 patients who underwent parathyroidectomy; with one patient having two operations. Forty-nine preoperative ultrasound localization studies were performed. Ultrasound sensitivity of correct localization of abnormal parathyroids was 41% with a false positive rate of 25%. Twenty-two sestamibi scans identified 14 abnormal parathyroids. Sestamibi scanning had a sensitivity of 32% for correct localization and a false positive rate of 32%. There were 16 different radiologists or nuclear medicine physicians involved with the nuclear medicine scans, and 22 different radiologists involved in the preoperative ultrasound scans. Forty-seven patients were cured of hyperparathyroidism after a primary operation, with a total of 48 patients in all being cured following re-exploration. One patient was lost to follow up. The success of primary exploration was therefore 96% and following re-exploration this increased to 98%. CONCLUSION: We found preoperative localization studies to have low sensitivities and high false positive rates. To move successfully towards MIP, we need to identify a radiologist with a special interest in localization studies to achieve greater accuracy.