Levothyroxine Suppressive Therapy Research Articles

7235 Papillary Thyroid Carcinoma in a Hyperfunctioning Thyroid Nodule

Abstract Disclosure: J. Yang: None. P.V. Nadkarni: None. Background: The prevalence of malignancy in a hyperfunctioning or hot thyroid nodule is considered to be low. According to the 2015 American Thyroid Association Guidelines, no cytologic evaluation is routinely recommended for hyperfunctioning nodules since they are rarely associated with malignancy (1). We present a case of a 71-year-old female with a hot nodule containing papillary thyroid cancer. Clinical Case: A 71-year-old female with Type 1 diabetes mellitus and coronary artery disease on dual antiplatelet therapy was found to have a 1.5 cm firm, non-tender right-sided thyroid nodule on a routine physical exam. Laboratory tests demonstrated low TSH <0.01 (normal 0.36 - 3.74 m[IU]/L) and FT4 level elevated at 1.62 (normal 0.76 -1.46 ng/dL). She noticed palpitations and started on low dose Methimazole. Thyroid ultrasound results showed a 2.1 x 2.0 x 2.0 cm right inferior lobe thyroid nodule. This thyroid nodule appeared mixed cystic and solid, hypoechoic, not taller than wide, with ill-defined margins and peripheral calcifications (ACR TI-RADS risk category: TR4). Nuclear medicine thyroid uptake scan demonstrated focally increased activity in the right lower pole corresponding with her right inferior thyroid nodule seen on ultrasound. Remainder of the gland appeared suppressed. She was recommended for ultrasound-guided fine needle aspiration biopsy of her right inferior thyroid nodule, given concerning characteristics on ultrasound findings despite results consistent with a hot nodule. Timing of her antiplatelet therapy was coordinated with her cardiologist, and her biopsy procedure scheduled after she stopped dual antiplatelet therapy. Her FNA results showed clusters of follicular cells with nuclear and architectural atypia, suspicious for papillary thyroid carcinoma. She underwent right thyroid lobectomy. Surgical pathology revealed 2 foci of papillary thyroid carcinoma, follicular variant (2.0 cm, 0.1 cm) and confined to the thyroid. All regional lymph nodes were negative for tumor. Methimazole was discontinued post-operatively, and she started Levothyroxine suppression therapy. Discussion: We present a rare association of papillary thyroid carcinoma presenting as a hot thyroid nodule. Though uncommon, detection of a hyperfunctioning thyroid nodule does not exclude the possibility of thyroid carcinoma and warrants careful evaluation. Clinicians should retain a high index of suspicion particularly when ultrasonography demonstrates findings suspicious for malignancy and consider additional evaluation with fine needle aspiration. Reference: (1) Haugen BR, Alexander EK, Bible KC et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016 Jan;26(1):1-133. Presentation: 6/2/2024

Long-Term Effects of 0.1 mg Recombinant-Human-Thyrotropin-Stimulated Fixed-Dose Radioiodine Therapy in Patients with Recurrent Multinodular Goiter after Surgery.

(1) Background: After thyroid malignancy is ruled out, treatment options for multinodular goiter patients include surgery, levothyroxine suppressive therapy, and 131-I therapy. Surgery effectively reduces goiter size but carries risks of surgical and anesthetic complications. 131-I therapy is the only nonsurgical alternative, but its effectiveness diminishes with goiter size and depends on iodine sufficiency. This study aimed to assess the efficacy and safety of 0.1 mg rhTSH as an adjuvant to a fixed dose of 131-I therapy in patients with a recurrence of large multinodular goiter, several years after the initial thyroidectomy. (2) Methods: 14 patients (13 females and 1 male), aged 59.14 ± 15.44 (range, 35-78 years) received 11mciu of 131-I, 24 h after the administration of 0.1 mg rhTSH. The primary endpoint was the change in thyroid volume (by ultrasound measurements) as well as in the diameter of the predominant nodule during a follow-up period of 10 years. Secondary endpoints were the alterations in thyroid function and potential adverse effects. (3) Results: A significant decrease in the volume of initial thyroid remnants (32.16 ± 16.66 mL) was observed from the first reevaluation (at 4 months, 23.12 ± 11.59 mL) as well as at the end of the follow-up period (10 years, 12.62 ± 8.76 mL), p < 0.01. A significant reduction in the dominant nodule was also observed (from 31.71 ± 10.46 mm in the beginning to 26.67 ± 11.05 mm). (4) Conclusions: Further investigation is needed since this approach could be attractive in terms of minimizing the potential risks of reoperation in these patients.

Focus on Thyroid Cancer in Elderly Patients

Thyroid cancer is more aggressive in elderly patients due to biological causes related to age, histotype, and the advanced stage at diagnosis. In the elderly, both the diagnosis and treatment of thyroid cancer impact quality of life. This review aimed to collect and discuss the different therapeutic approaches in elderly patients affected by thyroid cancer. Our analysis examined the therapeutic surgical approach according to age and how this affects the prognosis of patients with thyroid cancer, along with how iodine 131 therapy is tolerated and how effective it is. Furthermore, we investigated whether levothyroxine suppressive therapy is always necessary and safe in elderly patients with thyroid cancer and the safety and efficacy of systemic therapy in the elderly. We also intended to identify peculiar features of thyroid cancer in elderly subjects and to evaluate how the disease and its treatment affect their quality of life.

SAT564 Metastatic Malignant Pleural Effusion In A Patient With Remote History Of FTC

Abstract Disclosure: D.M. Lee: None. M. Gong: None. C. Czerlanis: None. A. Arif: None. R. Arceo-Mendoza: None. Introduction: Differentiated thyroid follicular epithelial-derived cancers include Papillary (PTC) and Follicular Thyroid Cancer (FTC). FTC is less common, accounting for only 5-15% of all thyroid cancers. It is more common in older patients and spreads via hematogenous route, with distant metastases in 10-15% of patients, commonly in the lungs and bone. We describe an unusual case of a patient with a remote history of FTC who presents with recurrence more than 50 years later in the form of a malignant pleural effusion. Clinical Case: A 79/M with a remote history of FTC that was diagnosed in the 1960s presents with one week of L sided pleuritic chest pain and dyspnea. CXR on admission showed opacification of the L hemidiaphragm. A chest CT confirmed the L sided pleural effusion. Thyroid US showed surgically absent thyroid and a 1.1cm solid nodule in the L surgical bed. PET/CT demonstrated hypermetabolic rim of L pleural effusion with no uptake in the neck. Thoracentesis was done which showed exudative pleural fluid concerning for malignancy. Immunohistochemical stains were positive for TTF-1 and thyroglobulin, consistent with metastatic thyroid cancer. He also underwent L supraclavicular lymph node FNA with findings suspicious for metastatic thyroid cancer with follicular features, with NO nuclear features of PTC. On further history, the patient reports having radiation therapy for acne around age 17 and was then diagnosed with FTC in his 20s. He underwent total thyroidectomy and RAI treatment. He recalls being told that he had a few weeks to live, and an “experimental treatment” was offered at the time, which we suspect was cobalt radiation. The patient unfortunately was eventually lost to endocrine follow up but denies any known recurrence prior to this admission. Upon discharge, an I-123 WBS was performed showing multiple foci in the R neck. Uptake is also noted in bilateral lung base, greater on the left. He was treated with 250 mCi I-131. He is currently doing well overall, asymptomatic, and with stable surveillance imaging. He is on levothyroxine suppression therapy with Tg level on a downward trend. Clinical Lesson/Conclusion: Involvement of pleural fluid by metastatic thyroid cancer though reported, is relatively rare, accounting for only less than 1% in all the patients with malignant pleural effusion. To our knowledge, there are no reported cases of malignant pleural effusions from metastatic FTC presenting remotely so many years after the initial diagnosis. The diagnosis of metastatic thyroid cancer in pleural fluid can be challenging and knowledge of the clinical context, even with remote history dating back 50 years ago just like in our case, and supporting immunohistochemical stains is essential for making the right diagnosis. Presentation Date: Saturday, June 17, 2023

Subcentimetric papillary thyroid carcinoma with extensive lymph node and brain metastasis: case report and review of literature.

We report a 61-year-old male patient without personal history of thyroid carcinoma or radiation exposure. In 2011, he presented with a cervical mass whose biopsy diagnosed a papillary thyroid carcinoma (PTC) in a lymph node metastasis (LNM). Total thyroidectomy with lymphadenectomy of central and ipsilateral compartment was performed. Histopathology identified a 2 mm follicular variant of PTC and LNM in 25/25 lymph nodes. The patient was treated with 150 mCi of radioactive iodine (RAI), followed by levothyroxine suppressive therapy. In 2016, a retrotracheal mass was diagnosed, suggesting local recurrence; patient was submitted to surgical excision and RAI therapy (120 mCi). Due to seizures, in 2019, a brain CT was performed that diagnosed brain metastases. The patient underwent debulking of the main lesion. Histopathology analysis confirmed a metastatic lesion with variated morphology: classical PTC and follicular pattern and hobnail and tall cell features. Molecular analysis revealed BRAFV600E in LNM at presentation and BRAFV600E and TERT promoter (TERTp) mutations in the recurrent LNM and brain metastasis. Based upon this experience we review the reported cases of subcentimetric PTC with brain metastases and discuss the molecular progression of the present case. Papillary microcarcinoma (PMCs) usually have very good prognosis with low impact on patient survival. PMCs presenting in elderly patients with LNM at diagnosis may carry a guarded outcome. Brain metastasis although rare indicate aggressive phenotypic features. Patient risk stratification of PMCs based on histopathological analysis and genetic testing may have a significant impact on prognosis providing therapeutic markers, that may predict disease progression and overall outcome.

Physical activity and reduced risk of fracture in thyroid cancer patients after thyroidectomy - a nationwide cohort study.

Levothyroxine suppressive therapy following thyroidectomy for thyroid cancer patients is considered as a risk factor for osteoporosis and fragility fractures. We evaluated the association of regular exercise and exercise habit change with fracture risk in adults older than 40 years who underwent thyroidectomy for thyroid cancer. We enrolled the patients who underwent thyroidectomy for thyroid cancer older than 40 years between 2010 and 2016 from the Korean National Health Insurance Service data, and they were followed through 2019. Based on the questionnaire of health examination within 2 years before and after surgery, whether regular exercise once a week was evaluated. The reference group for the statistical analysis was the continuing lack of physical activity group that did not exercise before or after surgery. For fractures newly diagnosed during the follow-up period, univariate and multivariate Cox regression analyses were performed for risk evaluation. We evaluated 74,774 subjects, of whom 2,924 (3.9%) experienced any fractures during a median follow-up of 4.5 years. Compared with the group consistently lack of physical activity, the group that exercised before and after surgery showed a significant decrease in the risk of any fracture, vertebral fracture, and hip fracture: adjusted hazard ratio 0.848 (95% Confidence Interval 0.771-0.932), 0.703 (0.591-0.836), and 0.405 (0.224-0.732), respectively. For vertebral fracture, a significant reduction in fracture risk was confirmed even in patients who started their regular exercise after surgery: adjusted hazard ratio 0.779 (0.648-0.936). The risk reduction for vertebral fractures upon the initiation of exercise was found to be significant in the high-risk groups of patients: women and total thyroidectomy patients. We suggest that maintaining or starting regular exercise after surgery may help prevent fractures in thyroid cancer patients older than 40 years who have undergone thyroidectomy.

Levothyroxine suppressive therapy in differentiated thyroid cancer treatment.

Levothyroxine therapy in management of diferentiated thyroid carcinoma (DTC) has been common practice for decades. Levothyroxine is being administered to patiens with DTC after total thyreoidectomy (with or without postopreative radioiodine treatment) not only to restore euthyroidism but to suppress the production of thyroid-stimulating hormone (TSH) as well because TSH is considered as a growth factor for thyroid follicular cells. However there has been a downside to this threatment recently. The main concerns are the known risks related to iatrogenic subclinical or even mild but clinicaly overt iatrogenic hyperthyroidism. Therefore individualized treatment approach aiming to balance between the risk of tumor recurence and the risks related to hypertyhroidism in view of pateints age, risk factors and comorbidities is essential. Close folow-up is therefore necessary with frequent dose adjustments according to target TSH values published in American Thyroid Association guidelines.

Complicated papillary thyroid cancer in young women: Case report

Abstract Introduction Despite papillary thyroid cancer (PTC) almost has a favorable prognosis, some patients for whom standard care is not sufficient due to the aggressive nature of their disease may exist. Here, we try to present a case report of young woman with a complicated PTC. Clinical Case A 32-year-old woman presented with a suspicious left lobe thyroid nodule, when a fine needle aspiration (FNA) cytology revealed classical PTC then underwent thyroidectomy with suppressive levothyroxine therapy was performed. During surveillance, a left supraclavicular lymph node (LN) was detected and an excisional biopsy was revealed metastatic PTC so that a total thyroidectomy with neck dissection was done, but unfortunately it was complicated by permanent tracheostomy. Two sessions of therapeutic radioactive iodine (RAI) were initiated at 150 mCi and then treated by suppressive levothyroxine therapy. One year later on, another palpable cervical LN (area IV) with evidence of non-sizable thyroid tissue were discovered. A stimulated thyroglobulin level=150.8 (3.5–77) ng/ml, anti-thyroglobulin=18.41 (&amp;lt;115) IU/mL and thyroid scintigraphy showed an intense radioiodine uptake in the thyroid bed (relatively large remnant thyroid tissue +/- residual disease), with no evidence of discrete RAI-avid cervical, mediastinal LN, or distant metastases. The patient is refusing further surgical intervention and Tyrosine kinase inhibitors may be a chance. Early wise approach and prediction the highly prevalent factors for aggressive PTC can judge the management plan. Conclusion Meticulous preoperative evaluation of LN metastasis is required for PTC patients with certain criteria to assess the management plan.

PAPILLARY CARCINOMA OF THE THYROGLOSSAL DUCT CYST: A CASE REPORT

Introduction. Thyroglossal duct cysts (TGDCs) can be diagnosed at any age. They are most common in women aged 30–40. Cysts can become malignant in 1% of patients. As a result, a very rare tumor – TGDC carcinoma ¬– develops. Some oncologists believe it is sufficient to perform surgery using the Sistrunk procedure. Other scientists insist on performing the Sistrunk procedure followed by thyroidectomy, lymph node dissection, and radioactive iodine ablation. In this report, we would like to share our successful experience in treating a patient with papillary carcinoma of PCOS. Case report. A 47-year-old woman had persistent midline neck swelling for three years. This lesion was completely asymptomatic. The patient had no cases of head and neck irradiation or a family history of thyroid gland diseases. Physical examination revealed a solid, movable, smooth mass measuring 6.0 × 5.0 × 4.0 cm on the anterior surface of the neck. The thyroid gland was of normal size, without nodules. Lymph nodes of the neck were not enlargement. During sticking out the tongue and swallowing, the tumor moved upwards. Neck ultrasound, CT scan, and fine-needle aspiration biopsy confirmed the presence of TGDC papillary carcinoma. All laboratory results, including thyroid hormones, were within normal ranges. The patient underwent the Sistrunk procedure, total thyroidectomy with central lymph node dissection, radioactive iodine ablation, and suppression of thyroid function with levothyroxine. The patient's follow-up period has been currently 110 months. There were no signs of relapse. Discussion. The etiology of the malignant transformation of the TGDC remains unknown. One of the main theories is the spontaneous development of ectopic thyroid tissue located in the cyst walls. Ultrasound, CT, and MRI are considered sufficiently informative methods. A fine-needle aspiration biopsy confirms TGDC carcinoma in 53% of patients before surgery. Virtually all patients with TGDC carcinomas undergo the Sistrunk procedure. In addition, some of them perform a total thyroidectomy. Criteria for total thyroidectomy are age older than 45 years, history of neck irradiation, tumor size greater than 4 cm, presence of regional metastases, and thyroid gland dysfunction. Postoperative radioiodine ablation and suppressive levothyroxine therapy are considered the best treatment before the start of the follow-up period. Conclusions. The treatment of patients with TGDC carcinomas should be personalized. Determining criteria should be the patient's age, gender, condition of the thyroid gland and regional lymph nodes, size of the primary tumor, resection margins, invasion of the tumor into the surrounding tissues, and family history of thyroid diseases.

Effect of Suppressive Levothyroxine Therapy on Bone Mineral Density in Young Patients with Differentiated Thyroid Carcinoma.

Suppressive levothyroxine therapy (sT4) is a cornerstone in the management of differentiated thyroid cancer (DTC). Long-term sT4 may affect bone mineral density (BMD). We evaluated the effect of sT4 on the bone mass of young DTC patients. In this cross-sectional study, BMD was evaluated via dual-energy X-ray absorptiometry in DTC patients younger than 25 years at diagnosis and undergoing sT4 for ≥1 year. The two control groups comprised patients matched for sex, age, and body-mass-index who were thyroidectomized for indications other than DTC and undergoing L-T4-replacement therapy, and healthy individuals with no prior known thyroid disease. Ninety-three participants were included (thirty-one in each group). There were no differences in the mean age, female sex (77.4% in all groups), or BMI between the sT4 group and each control group. The median TSH level was lower (0.4 [0.04–6.5] vs. 2.7 [0.8–8.5] mIU/mL, p = 0.01) and the mean L-T4 mcg/Kg levels were higher (2.4 ± 0.6 vs. 1.6 ± 0.3, p = 0.01) in the sT4 group compared to the L-T4-replacement therapy group. Lumbar spine, femoral neck, and total femur BMD were all similar among the groups. sT4 does not impact BMD in young DTC patients after a median time of suppression of 8 years. These findings may help in the decision-making and risk/benefit evaluation of sT4 for this population.

Recombinant human thyrotropin (rhTSH)-aided radioiodine treatment for non-toxic multinodular goitre.

Multinodular goitre is common in women. Treatments for non-toxic multinodular goitre include surgery, levothyroxine suppressive therapy, and radioiodine. Radioiodine therapy is the only non-surgical alternative for non-toxic multinodular goitre. However, a high amount of radioiodine is needed to enable the thyroid nodules to adequately take up the radioiodine, because the multinodular goitre takes up a low amount of iodine. Recombinant human thyrotropin (rhTSH) has been used to increase radioiodine uptake and reduce thyroid volume of the multinodular goitre. Whether the improved reduction of the goitre resulting from rhTSH-stimulated radioiodine therapy is beneficial to the person remains controversial. To assess the effects of recombinant human thyrotropin-aided radioiodine treatment for non-toxic multinodular goitre. We searched the CENTRAL, MEDLINE, Scopus as well as ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 18 December 2020. We included randomised controlled clinical trials (RCTs) comparing the effects of rhTSH-aided radioiodine treatment compared with radioiodine alone for non-toxic multinodular goitre, with at least 12 months of follow-up. Two review authors independently screened titles and abstracts for relevance. Screening for inclusion, data extraction, and risk of bias assessment were carried out by one review author and checked by a second. Our main outcomes were health-related quality of life (QoL), hypothyroidism, adverse events, thyroid volume, all-cause mortality, and costs. We used a random-effects model to perform meta-analyses, and calculated risk ratios (RRs) for dichotomous outcomes, and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We evaluated the certainty of the evidence using the GRADE approach. We included six RCTs. A total of 197 participants were allocated torhTSh-aided radioiodine therapy, and 124 participants were allocated to radioiodine. A single dose of radioiodine was administered 24 hours after the intramuscular injection of a single dose of rhTSH. The duration of follow-up ranged between 12 and 36 months. Low-certainty evidence from one study, with 85 participants, showed uncertain effects for QoL for either intervention. RhTSH-aided radioiodine increased hypothyroidism compared with radioiodine alone (64/197 participants (32.5%) in the rhTSH-aided radioiodine group versus 15/124 participants (12.1%) in the radioiodine alone group; RR 2.53, 95% CI 1.52 to 4.20; 6 studies, 321 participants; moderate-certainty evidence in favour of radioiodine alone). A total of 118/197 participants (59.9%) in the rhTSH-aided radioiodine group compared with 60/124 participants (48.4%) in the radioiodine alone group experienced adverse events (random-effects RR 1.24, 95% CI 0.94 to 1.63; 6 studies, 321 participants; fixed-effect RR 1.23, 95% CI 1.02 to 1.49 in favour of radioiodine only; low-certainty evidence). RhTSH-aided radioiodine reduced thyroid volume with a MD of 11.9% (95% CI 4.4to 19.4; 6 studies,268participants; moderate-certainty evidence). One study with 28 participants reported one death in the radioiodine alone group (very-low certainty evidence). No study reported on costs. RhTSH-aided radioiodine treatment for non-toxic multinodular goitre, compared to radioiodine alone, probably increased the risk of hypothyroidism but probably led to a greater reduction in thyroid volume. Data on QoL and costs were sparse or missing.

Аналіз впливу субклінічного гіпертиреозу на параметри кісткового метаболізму

Стан субклінічного гіпертиреозу можна розглядати як оптимальну модель для оцінки значення тиреотропного гормона (ТТГ) для кісткової тканини у клінічній практиці. Мета дослідження: здійснити порівняльний аналіз впливу субклінічного гіпертиреозу різного генезу на показники мінеральної щільності кісткової тканини (МЩКТ) і параметри кісткового обміну. Матеріали і методи. У дослідження в амбулаторних умовах було включено 112 жінок з діагнозом «субклінічний гіпертиреоз» і тривалістю менопаузи принаймні 5 років. Із числа обстежених ендогенний субклінічний гіпертиреоз спостерігався у 78 жінок (група I), екзогенний субклінічний гіпертиреоз на тлі супресивної терапії левотироксином (група II) — у 34. До контрольної групи (група III) увійшло 20 жінок без порушення функції щитоподібної залози. Результати. У дослідженні вперше проведений порівняльний аналіз стану кісткового метаболізму, показників МЩКТ, а також показників фосфору і кальцію, ліпідного спектру крові у жінок із субклінічним гіпертиреозом різної етіології. Позитивна кореляція маркерів кісткового метаболізму і вільного трийодтироніну (вТ3) як гормонів, необхідних для розвитку скелета і підтримки його гомеостазу, вказує на фізіологічний вплив паратгормона і вТ3 на кісткову тканину. Показано, що стан кісткового метаболізму і МЩКТ залежить не лише від вмісту ТТГ, але й від причин розвитку субклінічного гіпертиреозу. Висновки. У жінок постменопаузального періоду з ендогенним субклінічним гіпертиреозом спостерігається вірогідне зниження показників МЩКТ, більш виражене в кістках із кортикальною будовою. Виявлена негативна кореляційна залежність між маркерами кісткового метаболізму і ТТГ серед усіх пацієнтів, включених у дослідження.

The Assessment of Ventricular Arrhythmia Indicators Based on Electrocardiography in Patients With Differentiated Thyroid Cancer Followed Up With Levothyroxine Suppression.

Levothyroxine suppression therapy (LST) can cause some unfavorable effects on the cardiovascular system in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate ventricular arrhythmia predictors based on electrocardiography (ECG) in patients with DTC with LST. The ECG parameters including QT, corrected QT (QTc), Tp-e intervals, Tp-e/QT, and Tp-e/QTC ratios of 265 patients with DTC who met the inclusion criteria were compared with 100 controls. No difference was observed in the number of patients with DTC and controls with prolonged and borderline QTc interval (P = .273). Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were significantly higher in patients (P = .002, P = .02, P = .003; respectively). Linear regression analysis suggested that male gender was a predictor of higher Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios (β = 4.322, R2 = 0.024, P = .042; β = 0.016, R2 = 0.048, P = .005; β = 0.015, R2 = 0.044, P = .006, respectively). A higher serum fT4 level was found to be associated with a higher Tp-e/QT ratio (β = 0.018, R2 = 0.089, P = .007). Ventricular arrhythmia indicators were found to be higher in patients with DTC with LST. Defining ventricular arrhythmia predictors through ECG, an easily accessible cardiac diagnostic tool, can be potentially useful in raising awareness of the possible cardiac harm of LST.

SAT-510 Association of Myotonic Dystrophy with Autoimmune Endocrinopathies and Thyroid Carcinoma

Myotonic dystrophy (MD) is a multisystemic, autosomal dominant disorder associated with progressive muscle weakness, premature cataracts, frontal baldness, and cardiac disturbances. MD has been associated with several endocrinopathies including primary testicular failure, autoimmune endocrinopathies (hypothyroidism, hyperthyroidism, multinodular goiter, and Addison’s disease), thyroid carcinoma (primarily papillary), insulin resistance, and type 2 DM. Development of diabetes is thought to be related to formation of an insulin-resistant receptor because of aberrant regulation of mRNA. We describe the first reported case of a patient with MD associated with type I diabetes mellitus, Hashimoto’s thyroiditis with hypothyroidism, and follicular variant of papillary thyroid cancer. A 49-year-old female presented with acute congestive heart failure. The patient had history of type I DM diagnosed at the age of 26, complicated by mild background retinopathy, peripheral neuropathy, and nephropathy with microalbuminuria. The patient first noticed proximal muscle weakness 1 year ago that gradually progressed resulting in multiple falls. She had history of bilateral cataracts status post cataract extraction at age 26. She also had progressive dysphagia requiring PEG placement, and cognitive dysfunction with mood disorder and depression. Family history was significant for myotonic dystrophy in both maternal aunt and uncle as well as 2 cousins. EMG confirmed myotonia however genetic testing was not obtained due to cost. Due to her cognitive dysfunction and depression, she had difficult to control diabetes with HbA1c of 9.9%, and multiple previous admissions for DKA. She was status post total thyroidectomy in 2008 for follicular variant of papillary carcinoma and Hashimoto’s thyroiditis followed by I-131 therapy in 2009 and maintained on levothyroxine suppression therapy. Most recent Tg and Tg Ab were undetectable. On physical exam, the patient had a narrow, sallow face with temporal muscle atrophy, percussion myoclonus involving the thenar eminence of the hands, but no frontal balding. Work up showed LVEF of 20-24% with regional hypokinesis that led to catherization and PCI to LAD. The patient had recurrent NSTEMI which eventually resulted in CABG 1 year after presentation. The association of autoimmune endocrinopathies, thyroid carcinoma and MD suggests a possible cause and effect relationship between these disorders. In patients with diabetes and MD, previously described insulin resistance as well as cognitive dysfunction can hinder good glycemic control increasing risk for complications. Although patients with MD are typically treated by neurologists, evaluation and therapy of endocrine dysfunctions are also necessary.

MON-442 Tall Cell Variant of Papillary Thyroid Carcinoma Presenting Acutely as a Right Thyroid Mass and Thyroiditis - an Unusual Presentation

INTRODUCTIONAggressive malignant thyroid tumors (AMTT) can rarely present with signs and symptoms mimicking that of acute suppurative thyroiditis (AST). In its early course, correct diagnosis may be difficult but a prompt recognition is crucial. We report an interesting case of an aggressive papillary thyroid cancer with presenting acute symptoms masquerading as AST.CLINICAL CASEA 50-year-old Caucasian male was admitted for 2 day history of sore throat, odynophagia, low grade fever with a tender and enlarging right neck swelling, not improving with oral antibiotics. CT neck showed a 5.8 x 4.5cm mass in right thyroid lobe with shallow retropharyngeal effusion. Labs showed elevated WBC 10.7 x 109/L (4–10.5), ESR 20 mm/hr (0–12), CRP 92.93 mg/L (0.2–10), with negative rapid strep and IgM for viruses EBV and CMV. Thyroid function tests were normal. Ultrasound neck showed an ill-defined 6.5 cm hypoechoic mass with cystic component and increased vascularity and calcification, replacing the right thyroid lobe. Due to concern for thyroid abscess he underwent urgent aspiration. Fluid analysis and cultures were negative for bacterial source. FNA (fine needle aspiration) of one specimen was suspicious for follicular neoplasm with predominant hurtle cells and suspicious for thyroid neoplasm with papillary architecture in the other. Core biopsy was suspicious for papillary carcinoma but limited due to scant amount of tissue. Affirma unavailable due to insufficient RNA yield. Flow cytometry was negative for abnormal lymphocyte population. Repeat CT neck 3 weeks later was concerning for metastatic lymphadenopathy. He underwent total thyroidectomy with lymph node (LN) dissection and pathology showed papillary thyroid cancer, tall cell variant, tumor size 6 cm, predominantly hemorrhagic, extending to perithyroidal strap muscles and involving 5/6 LN in right trachea-esophageal groove. It was a stage I, pT3bN1aMx cancer. Subsequently, he underwent thyrogen stimulated I-131 ablation of residual thyroid carcinoma with pretherapy scan showing increased uptake in thyroid bed and a satellite lesion suspicious for LN metastasis. Post-ablative scan showed no other new lesions. He is now on levothyroxine suppressive therapy.CONCLUSIONEarly course of AMTT can rarely present as AST, both being progressive and fatal diseases. Our case had a typical presentation of AST, causing delay in diagnosis of his very aggressive form of thyroid cancer. Gross pathology showed predominantly hemorrhagic areas in the tumor with central necrosis, which was likely the cause of acute mass with systemic signs suspicious for infection. One should consider an alternative diagnosis in suspected cases of AST in the absence of positive cultures or lack of improvement with parenteral antibiotics. It is imperative to make a diagnosis without any delay as prognosis for either condition depends on prompt recognition and treatment.

Risk Factors for Predicting Osteoporosis in Patients Who Receive Thyrotropin Suppressive Levothyroxine Treatment for Differentiated Thyroid Carcinoma

Objectives:Endogenous hyperthyroidism accelerates bone turnover and shortens the normal bone remodeling cycle, which results in reduced bone density. It is estimated that suppressive levothyroxine (LT4) therapy also decreases bone density. The aim of this study was to define risk factors for osteoporosis development in patients under thyrotropin-stimulating hormone (TSH) suppressive treatment for differentiated thyroid cancer (DTC).Methods:Patients with a diagnosis of low or intermediate risk group DTC according to the American Thyroid Association 2015 guidelines and who have been receiving LT4 suppression therapy and were physically fit to undergo femur and lumbar vertebra bone density study were included in the study. Patients lacking information on demographic data, medical history, preoperative thyroid hormone status, or routine follow-up data were excluded from the study. A study form consisting of patient information on possible risk factors for osteoporosis such as gender, age, menopausal status, smoking, family history of osteoporosis, preoperative thyroid hormone status, postoperative hypoparathyroidism history, mean serum TSH levels, and duration of TSH suppression was created and filled out for each participant. Bone mineral densitometries of the femur and lumbar vertebrae were measured along with serum vitamin D and parathyroid hormone levels.Results:During TSH suppression (mean 7.2±4.5 years, range: 1-26), osteoporosis was detected in 89 (9.6%) patients. The mean time to develop osteoporosis was significantly different in patients with or without a family history of osteoporosis (15.3±0.4 versus 20.3±0.6 years; p=0.002). Similarly, the mean time to develop osteoporosis for was found to be significantly shorter in postmenopausal patients than that for premenopausal women (18.6±0.7 versus 20.4±0.4 years; p<0.001). Male gender (p<0.001), a family history of osteoporosis (p=0.001) and menopausal state (p<0.001) were identified as independent predictive factors for developing osteoporosis.Conclusion:Postmenopausal women, men, and patients with a family history who receive TSH-suppression treatment have a tendency to develop osteoporosis.

Effect suppresive therapy with levothyroxine on the state of the cardiovascular and sympathoadrenal systems

Thyroid hormones can affect the cardiovascular system directly by binding to nuclear thyroid receptors, as well as indirectly by changing the neuro – humoral status of the body as a whole. The aim of the work was to assess the effect of levothyroxine suppressive therapy on the regulation of the heart rate and activity of the sympathoadrenal system, as well as the level of cortisol in the blood of young patients with thyroid cancer. It is shown that the effect of suppressive therapy with levothyroxine on the state of the cardiovascular system is manifested in an increase in the risk of tachycardia and changes in heart rate variability associated with the body mass index. Patients with thyroid cancer had a sharp decrease in normetanephrine (norepinephrine metabolite) in the urine. The levels of metanephrine (metabolite of adrenaline) and dopamine in the urine was dependent on the tonus of the autonomic nervous system and blood pressure. The revealed shifts indicate that against the background of subclinical hyperthyroidism, the mechanisms aimed at stabilizing the heart rate and preventing the effects of hyperstimulation of thyroid and beta-adrenoreceptors of the myocardium are included.

SUN-592 Goiters and Levothyroxine Do Not Always Mix

Introduction Levothyroxine suppression therapy used to be the standard of care in the prevention of thyroid nodule and goiter growth. It has been found to be associated with complications in patients who are biochemically euthyroid. The practice remains widespread among practitioners despite recommendations against it from the ATA. Clinical Case A 74 year old female with a recently diagnosed goiter presented to the neurology intensive care unit as a transfer from an outside hospital for a cerebrovascular accident. Endocrinology was consulted for a suppressed TSH in the setting of new onset atrial fibrillation. About three months prior, she was referred by her primary care provider to see an endocrinologist for an asymptomatic goiter. Her TSH at the time was 2.376 uIU/mL (0.450-5.330 uIU/mL). The endocrinologist prescribed levothyroxine 150 mcg daily in an attempt to shrink the thyroid. Her levothyroxine dose was reduced to 125 mcg daily one month later after she was found to have TSH of 0.018 uIU/mL and FT4 of 2.4 ng/dL (0.71-1.85 ng/dL). Immediately prior to her admission to the hospital, she developed shortness of breath, aphasia, and right sided weakness. Her TSH was 0.086 uIU/mL and FT4 was 1.70 ng/dL on admission. At the time of the consult, the patient weighed 50 kg and her exam was notable for irregularly irregular tachycardia, aphasia, right sided weakness, and a large goiter. A diagnosis of iatrogenic hyperthyroidism was made. Her thyroid function tests normalized after a short course of methimazole for several days. The atrial fibrillation stabilized and her symptoms improved. She was eventually discharged to a rehabilitation facility. Conclusion Since TSH is a known growth factor for thyroid tissue, it has been postulated that suppressing TSH secretion may cause the stabilization as well as the shrinkage of thyroid nodules and goiters2. Concern regarding the safety of this practice developed as studies demonstrated an association with increased rates of arrhythmias and bone weakening2. The ATA now recommends against routine TSH suppression for benign thyroid nodules in iodine sufficient populations2. Despite these concerns, Bonnema et al showed that a large cohort of endocrinologists still prescribed levothyroxine suppression therapy when provided with an index case of a non-toxic nodular goiter1. This case highlights the dangers of levothyroxine suppression therapy for the shrinkage of thyroid nodules and goiters.

Langerhans' Cell Histiocytosis Masquerading as Metastatic Papillary Thyroid Cancer on F-18 FDG PET/CT: Diagnostic Dilemma Solved by PET/CT-Guided Biopsy.

We present a case of papillary thyroid cancer (post-thyroidectomy status) on regular treatment with suppressive Levothyroxine therapy. On follow-up at 6months after radioactive iodine ablation for remnant thyroid tissue, her thyroglobulin, and anti-thyroglobulin levels were 0.06ng/ml and 670IU/ml, respectively. Low-dose whole-body I-131 scan was negative. To look for the cause of isolated increased anti-thyroglobulin level, a whole-body 18F-FDG PET/CT was done which revealed multiple FDG-avid lytic skeletal lesions suggestive of metastases. For confirmation of diagnosis, 18F-FDG PET/CT-guided metabolic biopsy was done, which revealed Langerhans' cell histiocytosis on histopathological examination.

Subhyoid ectopic thyroid with a solitary colloid nodule in a 10-year-old girl: a rare diagnostic entity

Ectopic thyroid is a rare clinical entity, of which its presence in a subhyoid location is uncommon. It is equally rare to find a solitary thyroid nodule in the paediatric age group. We report a case of subhyoid ectopic thyroid in a 10-year-old girl, and its course over a span of 3 years. It was associated with a solitary colloid nodule, which eventually became symptomatic and did not respond to suppressive levothyroxine therapy. Hence surgical excision was done, and the child was put on replacement doses of levothyroxine.