Bilateral Central Neck Dissection Research Articles

9189 Medullary Thyroid Cancer Due To A Novel Ret Oncogene Mutation In A Patient On Glp-1 Receptor Agonist

Abstract Disclosure: K. Lamar: None. D. John: None. O. Faour: None. N. Meda: None. M. Kinaan: None. Introduction: Mutations in the RET oncogene have been associated with increased risk of endocrine neoplasia and Medullary Thyroid Cancer (MTC). We report the case of a patient who has a (c.3281G>A) RET mutation, previously reported as a variant of uncertain significance. Case: A 51-year-old lady presented to our endocrine clinic for routine management of hypothyroidism, type 2 diabetes mellitus, and obesity. She had been on liraglutide, metformin, glipizide, and basal insulin for several years with good diabetes management. She had also been on levothyroxine for more than 10 years. On physical examination, a right thyroid lobe nodule was palpated. We performed a neck ultrasound which revealed a solid, isoechoic nodule measuring (1.23 x 1.42 x 2.00 cm) with no calcifications. Fine needle aspiration was consistent with MTC. She denied family history of thyroid cancer. She was advised to stop liraglutide immediately given risk of MTC with GLP-1 receptor agonist use. Preoperative calcitonin and CEA were markedly high at 935 pg/mL and 60.3 ng/mL, respectively. Fortunately, Gallium Ga-68 dotatate PET CT showed no signs of metastatic disease. The patient underwent a total thyroidectomy with bilateral central and lateral neck dissection. No cervical metastases were noted on lymph node dissection. Genetic tumor testing demonstrated a mutation in the RET oncogene (c.3281G>A), which was previously reported as a variant with unknown significance. Screening for hyperparathyroidism and pheochromocytoma was normal. Postoperative calcitonin and CEA were <2.0 pg/mL and 3.2 ng/mL respectively. The patient continues MTC surveillance under the care of a multidisciplinary team. Discussion: Our case is the first case in literature that identifies the RET oncogene (c.3281G>A) mutation as a pathogenic variant associated with MTC. It also emphasizes the need for close monitoring for thyroid nodules in patients on GLP-1 receptor agonists and pre-existing thyroid disease, through a comprehensive physical examination and neck ultrasound if needed. Presentation: 6/2/2024

12556 Medullary Thyroid Cancer With Persistent Elevation Of Carcinoembryonic Antigen: Case Report

Abstract Disclosure: M.S. Campana: None. Introduction: Medullary thyroid Cancer (MTC) is a rare neuroendocrine tumor that originates from thyroid parafollicular C-cells and represents 5 % of all thyroid cancers. MTC can be sporadic (75%) or hereditary (25%) associated with multiple endocrine neoplasia type 2 syndrome (MEN2). Serum calcitonin (Ctn) and carcinoembryonic antigen (CEA) are its tumor markers. We report a case of persistently elevated CEA levels despite an undetectable Ctn in a patient with MTC after initial thyroid lobectomy. Description of the case: A 42-year-old woman self-identified a neck lump after intentional weight loss. A neck US showed a right lobe thyroid nodule which resulted as suspicious for malignancy (Bethesda V) with subsequent right lobectomy. Pathology reported a 2.6 cm unexpected MTC with negative surgical margins, extrathyroidal extension, angioinvasion, and lymphatic invasion. No cervical lymph nodes (LNs) were removed. Immunohistochemistry was positive for CEA, chromogranin A, synaptophysin, and Ctn. T2 Nx. One month after lobectomy, the Ctn was 10.5 (0-3.0 pg/mL) and CEA 205.2 (0-3.0 ng/mL Non-smoker; 0-5.0 ng/mL smoker). The patient was then referred to our clinic for further management. Laboratories showed normal serum calcium, PTH, and fractionated plasma metanephrine/normetanephrine. A 2-month post-operative Ctn was undetectable, but CEA was elevated at 24.5. Subsequently, we broaden imaging studies to include neck US, CT neck /chest with contrast, and MRI abdomen pelvis with contrast. The only remarkable finding was a 6.7 cm pelvic mass with normal Ca-125. Genetic testing was negative for germline RET, ruling out MEN2. Patient underwent completion left lobectomy with prophylactic bilateral central neck dissection. Pathology showed benign thyroid parenchyma with multinodular hyperplasia and 0/12 LNs. Because of concerning pelvic mass, the patient was referred to OB/GYN. She underwent a laparoscopic bilateral salpingo-oophorectomy. Pathology showed a follicular ovarian cyst, negative for malignancy. A year post-completion total thyroidectomy Ctn remains undetectable, and a CEA is normal at 1.3. Discussion: Because Ctn was already undetectable 1 month after lobectomy with persistent elevated CEA a complete total thyroidectomy with prophylactic bilateral central neck dissection was indicated to achieve operative cure. Ctn is specific to MTC but variable. CEA is more reproducible with less variability; however, it is not specific to MTC and can also be elevated in smokers, benign breast and genitourinary disease, emphysema, cirrhosis, and cancer of colon, rectum, liver, genitourinary, and lung. If residual disease is present, Ctn tends to be proportionally more elevated than CEA. When the opposite occurs, poorly differentiated MTC with possibility of distant metastases vs. a second primary malignancy vs. a distant benign neoplasm known to elevate CEA need to be ruled out. Presentation: 6/2/2024

Comparison of actual prognosis between unilateral and bilateral central neck dissection in modified radical neck dissection patients with no clinical central lymph node metastasis: a retrospective cohort study.

This study aimed to evaluate the long-term prognosis of contralateral central neck dissection (CND) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We compared the actual recurrence rate according to the extent of CND-ipsilateral and contralateral sides. A total of 708 PTC patients who underwent total thyroidectomy and concomitant ipsilateral or bilateral CND with ipsilateral lateral neck dissection between January 1997 and December 2022 at Samsung Medical Center were retrospectively analyzed. The median follow-up time was 118 months. Locoregional recurrence was observed in 26 patients (7.9%) and 30 patients (7.9%) in the ipsilateral and bilateral CND groups, respectively. There were 6 contralateral recurrence cases (1.8%) in the ipsilateral CND group and 6 cases (1.6%) in the bilateral CND group. There was only 1 contralateral central neck recurrence in the ipsilateral CND group. The incidence of hypocalcemia (P = 0.007) was higher in the bilateral CND group compared to the ipsilateral CND group. Surgeons may consider performing only unilateral CND-the side where tumor is for therapeutic purposes to reduce surgical complications.

Comparison of unilateral versus bilateral central neck dissection for clinically invasive papillary thyroid carcinoma.

The American Thyroid Association guidelines primarily recommend central neck dissection for papillary thyroid carcinoma with advanced primary tumors or clinically positive neck nodes. However, the appropriate extent of dissection remains unclear. We aimed to compare the rate of locoregional recurrence between unilateral and bilateral central neck dissection in invasive papillary thyroid carcinoma. Among 330 consecutive patients who underwent total thyroidectomy with central neck dissection for advanced papillary thyroid carcinoma, 212 underwent unilateral central neck dissection (UCND group) while 118 underwent bilateral central neck dissection (BCND group). We performed 1:1 propensity score matching, resulting in 99 matched pairs. Surgical outcomes and safety were compared between the two groups. Additionally, the impact of surgery on locoregional recurrence was compared using survival analysis. During a follow-up of 47.8 ± 20.4 months, 29 (8.8%) patients experienced locoregional recurrence within the entire study cohort. Following propensity score matching, no significant difference in recurrence-free survival was observed between the two groups (log-rank p = 0.516). Multivariate analysis revealed that only T4 staging was an independent risk factor for locoregional recurrence (p = 0.006). The mean number of total and metastatic central lymph nodes retrieved were significantly greater in BCND group (14.1 vs. 9.3, p < 0.001 and 6.8 vs. 4.6, p = 0.005, respectively). There was no significant difference in postoperative stimulated thyroglobulin levels between the two groups (0.79 ng/mL vs. 1.44 ng/mL, p = 0.389). The present study demonstrates no prognostic benefit in conducting bilateral central neck dissection. Unilateral central neck dissection may be the preferred choice for clinically invasive papillary thyroid carcinoma.

The role of parathyroid autotransplantation for hypoparathyroidism following total thyroidectomy with bilateral central neck dissection.

Hypoparathyroidism is the most common complication for patients who undergo total thyroidectomy (TT) with bilateral central lymph node dissection (BCLND). The objective of this retrospective study was to investigate the relationship between parathyroid autotransplantation (PA) and postoperative hypoparathyroidism. Four hundred and sixty-five patients with papillary thyroid carcinoma (PTC) who underwent TT with BCLND (including prophylactic and therapeutic BCLND) by the same surgeon were enrolled in this retrospective study. They were divided into five groups based on the number of PAs. Group 0 was defined as no PA, while Group 1, 2, 3, and 4 were considered as 1, 2, 3, and 4 PAs during TT with BCLND, respectively. Transient and permanent hypoparathyroidism occurred in 83 (17.8%) and 2 (0.4%) patients who underwent TT and BCLND, respectively. The incidence of transient hypoparathyroidism increased gradually with an increase in the number of PAs. Compared with the previous group, Groups 2 and 3 had significantly more cases of transient hypoparathyroidism (p=0.03 and p=0.04, respectively). All cases of permanent hypoparathyroidism occurred in the patients without PA. Compared with Group 0, there were more removed central lymph nodes (RCLNs) in patients with one PA. Furthermore, Group 2 had more metastatic central lymph nodes(MCLNs) and RCLNs than Group 1.The number of PAs was the only identified risk factor for transient hypoparathyroidism after the multivariate logistic regression analysis. The median parathyroid hormone level recovered to the normal range within 1 month after surgery. With an increasing number of PAs, the possibility of transient hypoparathyroidism also increases in patients with PTC who undergo TT and BCLND. Considering the rapid recovery of transient hypoparathyroidism in 1 month, two PAs during TT and BCLND could be a good choice, leading to an increase in the central lymph node yield and no permanent hypoparathyroidism. However, this conclusion should be validated in future multicenter prospective studies.

The Oncologic Outcomes of Bilateral Central Lymph Node Dissection in Unilobar Papillary Thyroid Cancer and Its Risks: A Prospective Cohort Study.

Background Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. Thyroidectomy and central neck dissection (CND) are often recommended in all cases with proven differentiated thyroid cancer (DTC) and clinically positive lymph nodes (LNs), as well as in high risk for micro-metastasis patients with T3-T4 tumors or established metastatic nodes in the lateral compartments. Aims The aims of this study were to ascertain the role of performing bilateral central LN dissection in unilobar PTC in improving the oncological outcomes and outline the risks involved. Methods This was a department-based, prospective cohort study. We included all 20 patients who had unilobar PTC and underwent total thyroidectomy with bilateral CND. A postoperative histopathological analysis was used to identify metastatic central LNs. Results Twenty total thyroidectomies plus bilateral CNDs were performed, of which 10 were prophylactic bilaterally (those with N0), and all 20 were prophylactic on the contralateral side of PTC. Conventional risk factors (age, tumor size, and extrathyroidal extension)were notassociated with performing a pCND. The presence of unilobar PTC by preoperative FNAC was the only factor associated with performing bilateral CND. Positive ipsilateral LNs were retrieved in 55% of CNDs, while positive contralateral LNs were retrieved in only 15% of the patients. Conclusions The incidence of contralateral cervical LN metastasis in patients with unilateral PTC is low, while there is clear evidence of postoperative morbidity from routine contralateral CND in unilobar PTC. Contralateral CND in patients with unilobar PTC may be reserved for high-risk patients: males, those aged ≤45 years, tumors larger than 1.0 cm, and cases with extrathyroidal extension and micro-calcification on ultrasound.

A modified, single-incision, gasless, endoscopic thyroidectomy and bilateral central neck dissection via axillary approach technique for bilateral papillary thyroid microcarcinoma: A preliminary report

BackgroundOur objective was to assess the viability and oncological security of a gasless, transaxillary single-incision endoscopic procedure for performing total thyroidectomy and bilateral central neck dissection (TT + BCND). This study focused on patients diagnosed with bilateral papillary thyroid microcarcinoma (PTMC). MethodBetween April 2020 and November 2021, 22 patients with bilateral PTMC underwent single-incision, gasless, transaxillary endoscopic TT + BCND. The patients’ clinicopathologic characteristics, surgical completeness and complications were analyzed. ResultSingle-incision, gasless, transaxillary endoscopic TT + BCND was successful performed in all patients. The median (IQR) total surgical time was 143 (85–160) min. Only two patients experienced transient unilateral RLN palsy or transient hypocalcemia. All these complications resolved within 1 month after surgery. The median duration of hospital stay after surgery was 4 (3–4.5) days. The median hospitalization expense for these patients was 3848 (3781–4145) USD. The median number of lymph node yielded was 10.5 (8–15). The cosmetic outcomes were well-received by all individuals. ConclusionIn certain cases, gasless, transaxillary endoscopic TT + BCND procedure performed through a single incision proved to be a secure alternative for managing bilateral PTMC.

Central node dissection from the perspective of lateral neck node metastasis in papillary thyroid carcinoma

ObjectivesControversy exists on how to handle central lymph nodes in papillary thyroid carcinoma, particularly regarding indications for prophylactic central neck dissection (CND). Central node metastases are more difficult to diagnose preoperatively than lateral node metastases. MethodsWe enrolled 493 patients with papillary thyroid carcinoma treated at our department in the past 22 years. Metastatic lymph nodes were diagnosed preoperatively mainly by ultrasonography. In principle, CND was performed for all cases; ipsilateral CND was performed for hemithyroidectomy, and bilateral CND was performed for total thyroidectomy. Lateral neck dissection (levels II to V; LND) was performed for metastases to lateral neck lymph nodes (clinical node (cN) 1b). ResultsThe cN stage was cN0 in 365 patients, cN1a in 10, and cN1b in 118. Of the 357 patients with stage cN0 who underwent CND, 42.9 % had pathologically positive nodes (pN+) in level VI, and of the 118 with stage cN1b who underwent CND, 78.0 % had pN+ in level VI. Cases with advanced T stage were significantly more common with pN+ in level VI. Level VI metastases were significantly associated with pN+ in level IV. As the total number of pN+ at each level of the lateral neck increased, the rate of patients with pN+ in level VI increased, and in patients with 3 or more pN+, about 85 % had level VI metastases. ConclusionBecause about half of the patients with cN0 patients had pN+ in level VI, and the rate of pN+ in level VI in each clinical T stage was 46 to 65 %, prophylactic CND should be performed, considering the various clinical benefits. Central nodes will have metastases in about 80 % of cases with lateral node metastases, requiring more accurate dissection. In lateral node metastases, there is a significant association between metastases in levels IV and VI.

A Case of Metastatic Papillary Thyroid Carcinoma in Neck Lymph Nodes Without Primary Tumor in Thyroid Gland.

Metastatic papillary thyroid carcinoma in the lymph nodes without a primary tumor in the thyroid gland is rarely reported. We report the case of a 63-year-old male who had a left neck level II palpable mass. A left cervical mass had previously undergone 2 central needle biopsies, but only atypical cells had been identified. His prior medical history included surgical treatment for prostate cancer 11 years ago. There was no suspicious primary tumor in the endoscopic examination. After the excisional biopsy, the pathologic finding was metastatic papillary carcinoma from the thyroid, and there were no aberrant findings in the thyroid sonography. The patient underwent a complete thyroidectomy, bilateral central neck dissection (CND), and left level IV dissection, along with postoperative radioactive iodine (RAI) therapy. No thyroid lesion and no more positive lymph nodes were found in the final pathology report. Three months later, a radioiodine nuclear scan was performed, although it revealed no abnormal iodine uptake.

Unpredictable nightmare in thyroid surgery: Incidental Parathyroidectomy

Background: Incidental removal of the parathyroid gland is an unwanted minor complication of thyroidectomy and would occur even in experienced centers. The purpose of this study was to evaluate our clinic’s outcomes, incidence, and risk factors for incidental parathyroidectomy. &#x0D; Methods: A total of 627 patients with an average age of 50.74±12.68 years were included in the study. Seventy-eight point nine percent of the patients had bilateral total thyroidectomy, 11.2% had a total lobectomy with isthmectomy, 4.8% had completed thyroidectomy, 4% had bilateral total thyroidectomy with bilateral central dissection and 1.1% had bilateral subtotal thyroidectomy. Incidental parathyroidectomy was observed in 6.4% (n=40) of all patients.&#x0D; Results: There was a significant correlation between incidental parathyroidectomy and bilateral total thyroidectomy and bilateral central neck dissection. There were no statistically significant differences between the incidental and nonincidental parathyroidectomy group with respect to age and gender. While the preoperative diagnosis of hyperthyroidism (20.6% vs 7.5%) was significantly higher in the non-incidental parathyroidectomy group than in the incidental parathyroidectomy group, and the diagnosis of malignancy was significantly higher in the incidental parathyroidectomy group (32.5% vs. 11.6%, p=0.001). Regarding parathyroid localization, our incidental parathyroidectomy rate was higher in intrathyroidal localized cases. Postoperative transient hypocalcemia (62.5%) was higher in the incidental parathyroidectomy group than in the non-incidental parathyroidectomy group (34.4%, p

Prophylactic bilateral central neck dissection does not improve the short term response to surgery and radioiodine ablation in differentiated thyroid cancer

Prophylactic bilateral central neck dissection does not improve the short term response to surgery and radioiodine ablation in differentiated thyroid cancer

Comparative Study between Total Thyroidectomy with Ipsilateral versus Bilateral Prophylactic Central Neck Dissection in Patients with Clinically Node – Negative Papillary Thyroid Carcinoma. A Meta-Analysis

Abstract Background Papillary thyroid carcinoma (PTC) accounts for &amp;gt; 80% of all thyroid malignancies. It is generally slow-growing and the overall prognosis is excellent, with 5-year, 10-year, and 20-year survival rates of 94%, 89%, and 87%, respectively. Aim of the Work The aim of this study is to compare between unilateral PCND and bilateral PCND in patients with clinically unifocal cN0 PTC using meta-analysis approach Methodology A Systemic review and meta-analysis Study was performed after the data extraction process. Five studies comparing the out-comes of unilateral PCND and bilateral PCND procedures in adult patients with PTC CN0 were included in this study. The publicly available literature on PubMed, and, the Web of Knowledge, and the China Journal Net, EMBASE, Cochrane Library, and Scopus databases and the ClinicalTrials.gov registry. Published from January 2005 to December 2020 concerning TT plus ipsilateral PCND versus TT plus bilateral PCND for PTC CN0 will be retrieved by searching the national and international online databases. Results The result of our study revealed that: Bilateral central neck dissection had higher insignificant operative time than ipsilateral one, bilateral central neck dissection had higher overall significant complications rate than ipsilateral one, bilateral central neck dissection had higher significant permanent hypo PTH and insignificant hematoma, seroma, and transient hypo PTH rate than ipsilateral one, ipsilateral central neck dissection had higher insignificant PRLNP, TRLNP rate nearly equal with bilateral one, ipsilateral CND appears to be sufficient in patients with tumors&amp;lt;1 cm as bilateral central neck dissection had higher insignificant tumor size than ipsilateral one, there was no statistically significant difference found between unilateral PCND and bilateral PCND regarding rate of recurrence. Conclusion We suggest that, ipsilateral central neck dissection may be a reasonable surgical option for prophylactic CND in unilateral PTC with clinically negative lymph nodes because of its lower rates of contralateral paratracheal node metastasis and transient hypoparathyroidism and lower complications than bilateral pCND. and effective for selected patients undergoing a total thyroidecto- my for cN0 unilateral PTC.

Clinico-pathological initial outcome of a newly adopted novel surgical technique for nodal metastatic thyroid cancer at a large-volume centre in a high-income developing country.

Thyroid cancer is the most common tumour in the endocrine system. In the past decade, the incidence of lymph node metastasis has increased, and so has the patient demand for a smaller scar. This research reports the surgical and patho-oncological short-term outcomes of a novel, minimally invasive neck dissection approach for thyroid carcinoma with lymph node metastases at the UAE's leading endocrine surgery centre. This study employed a prospectively maintained surgical database to retrospectively analyse relevant parameters such as surgical complications, including bleeding, hypocalcaemia nerve injury and lymphatic fistula, as well as oncological metrics such as the type of tumour and the ratio of lymph node metastasis to the number of harvested lymph nodes in 100 patients that underwent open minimally invasive selective neck dissection. The study comprised 50 patients with thyroidectomy, with bilateral central compartment neck dissection (BCCND; 50%); 34 with thyroidectomy, BCCND and selective bilateral lateral compartment neck dissection (BLCND; 34%); and 16 patients with selective unilateral central and lateral compartment neck dissection by recurrent nodal disease (ULCND; 16%). The female-to-male gender ratio was 78:22, with median ages of 36 and 42 years, respectively. Histopathology findings revealed that 92% of patients had papillary thyroid cancer (PTC) and 8% had medullary thyroid cancer. The mean total number of lymph nodes removed was 22 in the BLCND group, 17 in the ULCND group and 8 in the BCCND group (p = 0.001). Furthermore, the average lymph node metastasis was significantly higher in the BLCND group (p = 0.002). The percentage of temporary hypoparathyroidism was 29.8% and it persisted for 1.3%. The lateral compartment dissection morbidity was as follows: Four male patients with tall cell infiltrative PTC presented with pre-existing vocal cord paresis, necessitating nerve resection and anastomosis, and two more developed it after surgery (1.1% of the nerve at risk). Lymphatic fistulas occurred in four patients (4%) who were treated conservatively. Two patients were readmitted due to symptomatic neck collection. Horner syndrome was discovered in just one female patient. Male gender, aggressive histology and lateral compartment dissection independently increased surgical morbidity. In a high-volume endocrine centre, the adoption of minimally invasive selective neck dissections to treat nodal metastatic thyroid cancer did not increase specific cervical surgery complications.

재발성 갑상선암 수술 중 신경 모니터링 1예

The recurrent laryngeal nerve is a critical structure that must be carefully preserved during thyroid surgery. Any injury to this nerve can result in severe complications, including hoarseness, aspiration, and respiratory difficulty. Therefore, preserving the recurrent laryngeal nerve during surgery is crucial. In patients with a history of previous thyroid surgery, identification and preservation of the recurrent laryngeal nerve can be more challenging. We report a case of 43-year-old man diagnosed with recurrent papillary thyroid cancer who had previously total thyroidectomy with bilateral central neck dissection and right modified radical neck dissection due to papillary thyroid cancer. Re-do operation was successfully done without nerve injury using laryngeal nerve monitoring with electromyogram tube.

Abstract #1405977: Follicular Thyroid Cancer Presenting as Atypical Femur Fracture

Follicular thyroid cancer (FTC) is the second most common thyroid cancer and is known to metastasize hematogenously. The incidence of distance metastasis in FTC is approximately 6%-20% with bones and the lungs being the most common sites. Outcomes for patients with metastatic follicular thyroid cancer are poor, with a 10-year survival of 41%. 54-year-old female presented to endocrine clinic following an atypical fracture to her lesser trochanter. This occurred while applying minor force to the brake pedal in her car. Further evaluation with imaging revealed a 3.5cm boney lesion and a bone biopsy was consistent with metastatic follicular thyroid cancer. Her history included a left hemithyroidectomy in 2014 for a 5.2cm nodule that pathology initially reported as follicular adenoma. She was not followed by endocrinology after surgery. Ultrasound in 2013 showed two subcm right thyroid nodules. In 2022, she underwent FNA of two thyroid nodules and lymph nodes. She had a 0.9cm isthmus nodule that was suspicious for malignancy, 0.7cm right lower pole thyroid nodule that was benign. Two lymph nodes were also benign, but had Tg levels of 8 and 2ng/mL. Her imaging also showed pulmonary nodules and a right parietal bone lesion. She underwent completion thyroidectomy with bilateral central neck dissection and right lateral neck dissection. Pathology confirmed PTC follicular variant 0.6cm unifocal lesion in the right lobe with no angioinvasion, lymphatic invasion and no ETE. 53 lymph nodes were all negative. Due to her known distant disease, she is stage IVc. Pathology believes her bone lesion is consistent with the 0.6cm lesion and not the prior 5.2cm left nodule. She underwent treatment with I-131 with 198mCi. Post scan showed uptake in the left thyroid bed, right parietal bone and left lesser trochanter. Lung nodules did not demonstrate iodine avidity. Tg Levels prior to surgery was 2421. At time of RAI Tg was 2927 and was down to 234.6 three months after RAI. This patient was found to have boney metastasis of follicular thyroid cancer after presenting with an atypical femur fracture. This diagnosis was confirmed with her bone biopsy followed by pathology of the thyroid. RAI therapy is the most effective treatment for metastatic disease but its effect depends on the extent of uptake. Other treatments include surgery pending the location, or external beam radiation. This case highlights how a small follicular cancer can present with metastatic disease, causing morbidity for patients such as atypical fractures and pain.

Abstract #1399269: Never Too Old for Genetics: An Unusually Late Presentation of Medullary Thyroid Cancer in MEN2A

Virtually all germline RET pathogenic variant carriers develop medullary thyroid carcinoma (MTC). If possible, thyroidectomy should be performed prophylactically, before developing MTC. We describe a patient with pheochromocytoma found to have a germline RET p.Cys634Ser pathogenic variant at age sixty years who would be categorized as high risk based on genotype classification described by the American Thyroid Association and would have warranted prophylactic thyroidectomy at a young age. A 60-year-old man with history of hypothyroidism and osteopenia was found to have an adrenal mass during evaluation for kidney stones. It measured 4.1 x 3.2 x 3.8 cm on CT scan of abdomen and pelvis. MRI with and without gadolinium revealed a 4 cm left adrenal mass with T2 enhancement. Diagnosis of pheochromocytoma was confirmed with elevated levels of plasma free metanephrine and normetanephrine. The adrenal nodule showed avid uptake on PET CT Gallium-68 DOTATATE scan. No uptake was noted on the contralateral adrenal gland or in the neck. Patient underwent left adrenalectomy. Surgical pathology confirmed pheochromocytoma. Patient also had evidence of primary hyperparathyroidism (pHPT). Germline genetic analysis revealed a RET c.1900T >A(p.Cys634Ser) pathogenic variant confirming the diagnosis of multiple endocrine neoplasia type 2A (MEN2A). Calcitonin level was noted to be mildly elevated at 27.8 pg/ml. Subsequently, patient underwent total thyroidectomy, subtotal parathyroidectomy and bilateral central neck dissection. Surgical pathology revealed multifocal MTC, diffuse C-cell hyperplasia, and a foci of papillary thyroid microcarcinoma. Immunohistochemistry for calcitonin revealed diffuse C-cell hyperplasia. Patient was doing well on postoperative follow up and calcitonin level downtrended to < 2 pg/ml. Nearly all patients with MEN2A have either C-cell hyperplasia (CCH) or MTC, approximately 50% have a pheochromocytoma and 20-30% have pHPT. Age-related penetrance of CCH and hMTC is mutation dependent. Peak incidence in index patients is in the third decade of life in MEN2A. Our patient presented in the sixth decade of life. We decided to pursue genetic testing. The DOTATE scan did not show uptake in the neck and the calcitonin was only mildly elevated. However, as there is known complete penetrance of MTC in patients with MEN2A syndrome, patient underwent total thyroidectomy with central neck dissection with results of surgical pathology confirming presence of MTC. This case highlights the importance of considering genetic syndromes even in patients who present at older ages and challenges the classic genotype-phenotype correlation of the RET p.Cys634Ser pathogenic variant and MTC.

ESTIMation of the ABiLity of prophylactic central compartment neck dissection to modify outcomes in low-risk differentiated thyroid cancer: a prospective randomized trial

BackgroundProphylactic central neck dissection in clinically low-risk cT1bT2N0 papillary thyroid carcinoma is controversial, due to a large number of conflicting retrospective studies, some showing an advantage in terms of locoregional recurrence, others showing no advantage. These previous studies all show high rates of excellent response. We aim to demonstrate the non-inferiority of thyroidectomy alone as compared to total thyroidectomy with prophylactic central neck dissection in conjunction with adjuvant RAI 30 mCi with rTSH stimulation in terms of excellent response at 1 year.Trial design and methodsProspective randomized open multicenter phase III trial including patients with 11–40-mm papillary thyroid carcinoma (Bethesda VI) or suspicious cytology (Bethesda V) confirmed malignant on intra-operative frozen section analysis, with no suspicious lymph nodes on a specialized preoperative ultrasound examination. Patients will be randomized 1:1 into two groups: the reference group total thyroidectomy with bilateral prophylactic central neck dissection, and the comparator group total thyroidectomy alone. All patients will receive an ablative dose of 30mCi of radioactive iodine (RAI) within 4 months of surgery. The primary outcome is to compare the rate of excellent response at 1 year after surgery between the groups, as defined by an unstimulated serum thyroglobulin (Tg) level ≤ 0.2 ng/mL with no anti-Tg antibodies, an normal neck ultrasound and no ectopic uptake on the post-RAI scintiscan. Non-inferiority will be demonstrated if the rate of patients with excellent response at 1 year after randomization does not differ by more than 5%. Setting the significance level at 0.025 (one-sided) and a power of 80% requires a sample size of 598 patients (299 per group). Secondary outcomes are to compare Tg levels at 8 +/− 2 postoperative weeks, before RAI ablation, the rate of excellent response at 3 and 5 years, the rate of other responses at 1, 3, and 5 years (biochemical incomplete, indeterminate, and structurally incomplete responses), complications, quality of life, and cost-utility.Discussion (potential implications)If non-inferiority is demonstrated with this high-level evidence, prophylactic neck dissection will have been shown to not be necessary in clinically low-risk papillary thyroid carcinoma.Trial registrationNCT 03570021. June 26,2018

PSAT281 Crico-tracheal Resection with End-to-End Anastomosis for Locally Advanced Thyroid Cancer: A Case Series of Early Postoperative Outcomes of a Low-Income Country from Latin America

Abstract Introduction Tracheal invasion is a poor prognostic factor in patients with aggressive thyroid cancer. Crico-tracheal resection and primary anastomosis (CTRA) is the preferred surgical technique. Appropriate resection can improve early postoperative outcomes and long-term oncological outcomes. A recent systematic review of eastern literature showed a moderate rate of postoperative complications. However, there is a paucity of data regarding early postoperative complications in Latin America. Therefore, the aim of this report is to describe the early postoperative outcomes of three patients with thyroid cancer invading the trachea who underwent CTRA in two tertiary referral centers (1 public and 1 private) in a low-income country. Clinical Cases There were 2 females (F1: 53 y, F2: 55 y) and 1 male (M1: 53 y) patients from Ecuador. Patient F1 had follicular variant of papillary thyroid cancer (PTC) and was operated on in the public center and patients F2 and M1 had classic variant of PTC. Neck CT and perioperative flexible endoscopy were performed for airway invasion assessment. All patients underwent total thyroidectomy with circumferential CTRA. Patient F1 had a right lobe thyroid tumor with intraluminal invasion of the 5th tracheal ring up to the cricoid cartilage, the recurrent laryngeal nerve (RLN) and common carotid artery, and bilateral central neck lymph node metastasis. She underwent bilateral central neck dissection, carotid shaving, and RLN resection. Patient F2 showed an enlarged, multinodular thyroid invading the 4th up to the 1st tracheal ring, without luminal compromise. There was no invasion to other structures. Patient M1 had a right lobe thyroid tumor, with intraluminal invasion of the 4th tracheal ring up to the cricoid cartilage and invasion of the RLN. He underwent RLN resection. Patient F1 and M1 were classified as Shin IV and patient F2, Shin III. Regarding the 30-day postoperative complications, patient F1 had tracheostomy infection on day 5, tracheal dehiscence and anastomotic dehiscence that caused massive bleeding, cardiorespiratory failure and death on day 8. Patient M1 only presented mild bleeding through the traqueostomy tube on day 1, non-compressive cervical hematoma on day 2, and was discharged on day 5. Patient F2 had no complications and was discharged on day 3. The last 2 patients were decanulated successfully at the 2-week follow-up and received adjuvant radioactive iodine. Conclusions CTRA seems to be a safe procedure with moderate postoperative complications, low mortality, and zero tracheotomy-dependency rates in patients operated in Ecuador. Our results are similar to those described in the international literature. Further studies are needed to confirm these results and draw robust conclusions. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Preoperative supplementation of calcitriol and calcium relieves symptom and extent of hypocalcemia in patients undergoing total thyroidectomy and bilateral central compartment neck dissection: A prospective, randomized, open-label, parallel-controlled clinical study.

BackgroundHypocalcemia is the most common complication that challenges surgeons performing total thyroidectomy. Conventional postoperative calcium and calcitriol supplement has been reportedly effective; however, a time lag has been reported before taking effect. Therefore, the role of preoperative strategy is yet to be determined.Study designIn this prospective, randomized, open-label, parallel-controlled phase II clinical study (registration number: ChiCTR2200059815), a short-term preoperative administration of calcitriol and calcium was proposed in 210 patients undergoing total thyroidectomy and bilateral central compartment neck dissection. Patients were recruited and randomized (1:1:1) into three groups: (A) combined (preoperative calcitriol and calcium), (B) calcium only (preoperative calcium only), and (C) control (no preoperative intervention). Finally, a total of 172 patients were qualified for final analysis.ResultsOur data showed that 16 of 63 patients (25.4%) in the combined group had symptomatic hypocalcemia, whereas more patients from the control group (25 of 57 patients, 43.9%, P = 0.033) had symptomatic hypocalcemia. Further, the postoperative calcium level in the combined group is higher than in the control group (2.15 ± 0.15 vs. 2.09 ± 0.15 mmol/L, P = 0.031). Moreover, patients from the combined group showed lower calcium rates of <2.00 mmol/L (12.7% vs. 28.1%, P = 0.036). Remarkably, compared with the control group, patients with transient hypoparathyroidism in the combined group showed fewer rates for both symptomatic and biochemical hypocalcemia (28.6% vs. 61.1% for symptomatic hypocalcemia; 47.6% vs. 75% for biochemical hypocalcemia). Patients without transient hypoparathyroidism in all three groups showed no significant difference in rates for either symptomatic or biochemical hypocalcemia, indicating that this preoperative strategy is only effective for patients with transient hypoparathyroidism. We did not observe such beneficial effects in patients from the calcium group.ConclusionsPreoperative administration of calcitriol and calcium could reduce symptomatic and biochemical hypocalcemia, especially for those with transient hypoparathyroidism. Moreover, this maneuver could be recommended as a clinical routine in patients undergoing total thyroidectomy and bilateral central compartment neck dissection.Clinical Trial Registration http://www.chictr.org.cn/edit.aspx?pid=164316&htm=4, identifier ChiCTR2200059815.

Pretracheal Lymph Node Subdivision in Predicting Contralateral Central Lymph Node Metastasis for Unilateral Papillary Thyroid Carcinoma: Preliminary Results.

BackgroundThe aims of this study were to assess the clinical value of pretracheal lymph node subdivision in identifying patients with contralateral central lymph node metastasis (CLNM) and risk factors for occult contralateral CLNM in unilateral PTC.MethodsA total of 139 unilateral PTC patients with a clinically node-negative neck (cN0) who underwent bilateral central neck dissection (CND) were prospectively enrolled. Intraoperatively, the pretracheal region was further divided into ipsilateral and contralateral subregions. Ipsilateral and contralateral pretracheal lymph nodes (LNs) as well as other CLNs (prelaryngeal, ipsilateral paratracheal and contralateral paratracheal) were labeled separately and sent for pathological examination. Demographic and clinicopathologic variables were analyzed to identify factors predictive of contralateral CLNM.ResultsOf 139 patients, bilateral CLNM was present in 37 (26.6%) patients. Contralateral pretracheal LNM was significantly associated with contralateral CLNM. In multivariate analysis, prelaryngeal LNM (P = 0.004, odds ratio = 3.457) and contralateral pretracheal LNM (P = 0.006, odds ratio = 3.362) were identified as risk factors for contralateral CLNM. Neither neck recurrence nor distant metastasis was observed within the mean follow-up duration of 9.1 ± 1.8 months.ConclusionsIn most unilateral cN0 PTCs, performing ipsilateral CND is appropriate, while patients presenting with evident nodal disease intraoperatively or preoperatively in the contralateral central neck should undergo bilateral CND. Intraoperative re-evaluation of prelaryngeal and contralateral pretracheal LNs may be helpful in determining the extent of CND.