Incidental Thyroid Malignancy in Surgical Patients With Benign Thyroid Disease.

INTRODUCTION: The rate of incidental thyroid malignancy (ITM) has increased in recent decades. However, the factors associated with ITM remain uncertain. This study analyzes the rate of ITM in patients after surgical resection for benign thyroid disease (BTD) without preoperative suspicion of thyroid malignancy and its associated sociodemographic factors. MATERIALS AND METHODS: A retrospective study of prospectively collected data reviewed data from 2528 patients who underwent initial thyroidectomy for BTD at a tertiary academic medical hospital between 2011 and 2022. Patients were excluded if they had a known history of thyroid cancer, radiation exposure, suspicious thyroid ultrasound features, and/or fine needle aspiration results. ITM rate was analyzed along with patient demographics, body mass index (BMI), tumor size, and invasive features. RESULTS: Among 345 patients with BTD (mean 53.6 y, SD = 14.5), 22.9% (79/345) had ITM on final histopathology. Most patients were women (87.0%), White (87.0%), and Hispanic (56.8%), with an average BMI of 29.6 (SD = 6.56). BTD type was associated with ITM (P < 0.001), with nontoxic multinodular goiter exhibiting the highest incidence (36.0%). Higher BMI emerged as a predictor of higher rate of ITM (OR = 1.057, P = 0.007). Other sociodemographic variables did not show significant associations. CONCLUSIONS: The study identified a higher rate of ITM than previously reported as well as an association between higher BMI and increased rate of ITM. This highlights a potential link between obesity and ITM not previously identified. Patients with higher BMI and BTD may benefit from further surveillance.

Chronic Lymphocytic Thyroiditis May Limit the Utility of Molecular Testing in AUS/FLUS Thyroid Nodules.

INTRODUCTION: Chronic lymphocytic thyroiditis (CLT) may increase the likelihood of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) results in thyroid nodules by fine needle aspiration (FNA). Gene expression classifier (GEC) and Thyroid Sequencing (ThyroSeq) may better stratify rate of malignancy (ROM) of AUS/FLUS thyroid nodules. This study compares the utility of molecular tests in determining malignancy in surgical patients with concomitant AUS/FLUS thyroid nodules and CLT. METHODS: A retrospective review of 1648 patients with index thyroid nodules who underwent FNA and thyroidectomy at a single institution was performed. Patients with concomitant AUS/FLUS thyroid nodules and CLT were subdivided into three diagnostic groups: FNA only, FNA with GEC, and FNA with ThyroSeq. Patients with AUS/FLUS thyroid nodules without CLT were subdivided into similar groups. Final histopathology of the cohorts was further stratified into benignity and malignancy and analyzed using Chi-squared statistics. RESULTS: Of 463 study patients, 86 had concomitant AUS/FLUS thyroid nodules and CLT with a 52% ROM, and the difference of ROM among FNA only (48%), suspicious GEC (50%), or positive ThyroSeq (69%) was not significant. In 377 patients with AUS/FLUS thyroid nodules without CL, ROM was 59%. ROM among these patients was significantly higher when molecular testing was used (FNA only 51%, suspicious GEC 65%, and positive ThyroSeq 68%; P < 0.05). CONCLUSIONS: Molecular tests may have limited value in predicting malignancy in surgical patients with concomitant AUS/FLUS thyroid nodules and CLT.

Depth of mediastinal extension can predict sternotomy need for substernal thyroid goiters.

BACKGROUND: Surgical excision of substernal thyroid goiters is usually achieved through a conventional transcervical approach, and transthoracic excision is rarely necessary. Currently, there are no clear guidelines for substernal thyroid goiters that may require a transthoracic approach. This study examined what preoperative factors were significantly associated with transthoracic surgical excision for substernal thyroid goiters. METHODS: A retrospective review of prospectively collected data of 109 patients with substernal thyroid goiters from a single institution was performed. The patients were stratified by transcervical and transthoracic approaches for substernal thyroid goiters. The factors possibly predictive of a transthoracic approach, including substernal extension beyond the thoracic inlet, patient-reported symptoms, tracheal deviation, and malignancy, were analyzed. Demographics including age, sex, and race, among others, were also studied. RESULTS: Of 1,080 patients who underwent surgical resection for multinodular goiter, there were 109 (10%) patients with substernal thyroid goiters. Of the substernal thyroid goiter group, 11 (10%) patients underwent partial sternotomy, whereas 6 (5.5%) underwent total sternotomy. On logistic regression, only substernal component of the thyroid goiter extending beyond the sternal notch into the mediastinum was statistically significant in predicting sternotomy (odds ratio 3.43, confidence interval 1.65-6.41, P < .001). Substernal thyroid goiters with mediastinal extension of ≥5 cm beyond the sternal notch showed a sensitivity of 94% and specificity of 86.5% to predict need of sternotomy. CONCLUSION: Patients with substernal thyroid goiters who exhibit progressive enlargement and/or compressive symptoms should undergo surgical excision. Although most are removed through the conventional transcervical approach, substernal thyroid goiters with a depth of mediastinal extension ≥5 cm have a high likelihood of requiring sternotomy.

Morbidity Associated With Surgical Removal of Substernal Thyroid Goiters.

INTRODUCTION: Surgical excision of substernal thyroid goiters (STG) can be challenging while minimizing postoperative morbidity. Postoperative complication rates associated with transcervical and transthoracic approaches (i.e., partial or total sternotomy) for STG compared to multinodular goiters (MNG) limited to the neck (i.e., non-substernal) remains unclear. This study examines postoperative morbidity related to surgical approaches in the removal of STG and MNG. METHODS: A retrospective review of prospectively collected data of 988 patients with STG and non-substernal MNG from a single institution between 2010 and 2021 was performed. Patients were stratified by STG and conventional non-substernal MNG limited to the neck excised by transcervical and transthoracic approach. Postoperative complications including neck hematoma requiring return to the operating room, permanent recurrent laryngeal nerve injury and hypocalcemia, and transient or temporary recurrent laryngeal nerve injury and hypocalcemia were identified. Demographics including age, sex, and race, among others, were analyzed. RESULTS: Of the 988 cases, there were 887 (90%) MNG and 101 (10%) STG. Of the STG cohort, 11 (11%) required a partial sternotomy and 4 (4%) required a total sternotomy. Permanent complication rates for non-substernal MNG and STG patients were 1.5% and 0.9%, respectively. Only transient or temporary hypocalcemia rates were statistically different between the STG and MNG cohorts (9.9% versus 3.8%, P < 0.001). CONCLUSIONS: Regardless of transcervical or transthoracic approach, postoperative complications associated with the surgical removal of STG are low in the hands of experienced, high-volume thyroid surgeons.

Transient Hypocalcemia After Total Thyroidectomy: The Obesity Paradox at Work?

INTRODUCTION: With increasing rates of obesity worldwide, a correlation between high body mass index (BMI) and postoperative morbidity after thyroid surgery remains unclear. Postoperative transient hypocalcemia is common after total thyroidectomy due to interruption of parathyroid function. This study examines the relationship between BMI and hypocalcemia after total thyroidectomy. MATERIALS AND METHODS: A retrospective review of prospectively collected data for 1135 patients who underwent total thyroidectomy for cancer, multinodular goiter (MNG), or Graves' disease between June 2009 and November 2020 at a single institution was performed. BMI groups followed the World Health Organization classification. Hypocalcemia was defined as serum calcium ≤8 mg/dL. Calcium levels measured on postoperative day 0 and the following morning were compared between the BMI groups. RESULTS: Of 1135 total thyroidectomy patients, 85% were women. The mean age and standard deviation of patients was 49 (± 13) y, with most of Hispanic origin (64%). Overall, 41.5% of patients had cancer, 45% nontoxic MNG, 5.8% toxic MNG, and 12% Graves' disease. Stratified by BMI, 27% of patients were normal, 34% overweight, and 39% obese. Overall, overweight and obese patients experienced less transient hypocalcemia at both time points compared to normal patients postoperatively (P = 0.01 and P = 0.009). Furthermore, overweight and obese patients with Graves' disease experienced less transient hypocalcemia at both time points (P = 0.04 and P = 0.05). There was no statistical difference in other groups. CONCLUSIONS: A protective role of higher BMI or "obesity paradox" for postoperative hypocalcemia may exist in those obese patients after total thyroidectomy.

Molecular Testing Has Limited Utility in the Surgical Evaluation of Bethesda III Thyroid Nodules.

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology has 6 diagnostic categories, each with an implied cancer risk of malignancy (ROM). Bethesda III, defined as atypia or follicular lesions of undetermined significance (AUS/FLUS) on fine needle aspiration (FNA), has an indeterminate ROM. This study investigates the utility of Afirma Gene Expression Classifier (GEC) and Thyroid Sequencing (ThyroSeq) molecular testing to predict malignancy in AUS/FLUS thyroid nodules. METHODS: A retrospective review of prospectively collected data of 1457 patients with index thyroid nodules who underwent FNA and thyroidectomy at a single academic institution was performed. Use of GEC or ThyroSeq for AUS/FLUS thyroid nodules was examined. GEC testing was reported benign or suspicious for malignancy whereas ThyroSeq testing was reported on a spectrum of low, intermediate or high ROM. Descriptive statistics were utilized to compare the ROM among AUS/FLUS thyroid nodules. RESULTS: Of 1457 patients with FNA thyroid cytology, 359 (25%) corresponded to AUS/FLUS results. There were 132 (37%) patients with GEC testing and 88 (24%) had ThyroSeq testing. ROM without GEC or ThyroSeq testing was 49%, whereas ROM with suspicious GEC was 55%. ROM with positive ThyroSeq was 73%. Among ThyroSeq patients, 43 had intermediate-risk mutations with 60% malignancy, and 23 had high-risk mutations with 96% malignancy (P < 0.01). CONCLUSION: Surgical patients with AUS/FLUS thyroid nodules have a high ROM. High-risk ThyroSeq testing may have some utility in predicting malignancy, but GEC and intermediate-risk TGC results have limited value. Surgeons should carefully consider the utility of molecular tests to determine surgical resection.