ResearchPad - thyroid-disorders-case-reports-iii https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[MON-459 Bilateral Killian-Jamieson Diverticulum Mimicking Thyroid Nodules]]> https://www.researchpad.co/article/elastic_article_8766 Background

In recent years, incidence and prevalence of thyroid and extrathyroid lesion is increasing in the worldwide due to increase awareness of medical check-up, and widespread use of imaging techniques. A Killian Jamieson diverticulum (KJD), a rare type of hypopharyngeal pulsion diverticulum outpouching from the lateral wall of the proximal cervical esophagus, was incidentally detected and likely to be misinterpreted as a thyroid nodule while performing thyroid sonography. Clearly differentiate between those lesions is essential to avoid unnecessary invasive procedure. Here we report a typical case of bilateral Killian Jamieson diverticulum mimicking thyroid nodules.

Clinical case

A 57-year-old Taiwanese man was referred to our endocrine outpatient department for further evaluation of thyroid nodules. The lesions were discovered while sonographic examination performed in the clinic for routine medical check-up. He denied having dysphagia, epigastric pain, odynophagia, halitosis, chronic cough or acid regurgitation, body weight loss, fever and dyspnea. He had no previous systemic disease and no prior radiation therapy. He lives in Nangang District, Taipei city. His body weight was 70 kg and BMI was 25. An examination of head and neck was unremarkable. Laboratory data revealed normal thyroid function (TSH: 0.67 uIU/ml; range 0.4~4.0, free T4: 0.83 ng/dl; range 0.9~1.8 and aTPO <1.0 IU/ml; range <5). Thyroid ultrasonography demonstrated oval, hypoechoic nodule-like lesions containing bright foci with acoustic shadow in the posterior aspect of the both lobes of thyroid gland. The rest of thyroid glands were normal appearance. An esophagography was performed and showed two contrast-filling anterior outpouching lesions at both sides of the cervical esophagus, around C7 level and both lesions were showing anterior outpouching appearance, consider Killian-Jamieson diverticulum. Taken together, he was diagnosed as KJD and clinical follow-up alone is suggested.

Clinical lessons

KJD is usually incidentally detected and misdiagnosed as a thyroid nodule containing punctuate microcalcification foci as found in papillary thyroid carcinoma. To differentiate these nodules, real time sonographic examination is important. Although rare, non-thyroid lesions originating from the esophagus should be considered in the differential diagnosis of the thyroid nodules to avoid unnecessary invasive fine needle aspiration of thyroid gland.

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<![CDATA[MON-480 Isolated Hyperthyroxinemia - Does Everyone Needs Treatment?]]> https://www.researchpad.co/article/elastic_article_8760 Background: Raised free thyroxine (T4) with normal thyroid stimulating hormone (TSH) levels should be identified and interpreted with caution. Some of these conditions do not need treatment. We present three cases with similar biochemical abnormalities from three different causes.

Case 1: A 62-year-old clinically asymptomatic lady was referred to us with Free T4 34.9 pmol/L (10.0 – 24.0 pmol/L), TSH 0.81 mU/L (0.2 – 5.0 mu/L) and negative TSH receptor antibodies (<0.9 IU/L). She was trialled on antithyroid drugs for 6 months. Her Free T4 stayed elevated between 29.0 – 35.0 pmol/L with normal TSH. We worked up for assay interference by running tests on two analysers, Roche Cobas e801 and Siemens ADIVA Centaur CP, both yielded similar results. Alpha1 glycoprotein subunits and SHBG were normal with clinical euthyroid status making TSHoma less likely. Serum protein electrophoresis did not detect any abnormal albumin. We were unable to perform equilibrium dialysis due to non-availability of facility at our centre. Due to strong clinical suspicion and family history of thyroid dysfunction that never needed a treatment, we tested her genetically for familial dysalbumineic hyperthyroxinemia (FDH) using mutation surveyor and fluorescent sequence analysis showed her to be heterozygous for c.725G>A ALB variant confirming diagnosis of FDH.

Case 2: A 65-year-old clinically asymptomatic lady, was referred to us with Free T4 28.8 pmol/L (10.0 – 24.0 pmol/L) and TSH 2.50 mU/L (0.2 – 5.0 mu/L). Given inappropriately normal TSH levels, we repeated her TFTs using 3 different analysers, Roche cobas e801, Siemens ADIVA centaur CP and Abbot ARCHITECT i1000SR. Roche and Siemens assays yielded similar results, however Abbot assay showed normal thyroid function tests with TSH 1.01 mu/L (0.4-5.0 mu/L) and free T4 18.7pmol/L (9.0-19.0 pmol/L), confirming assay interference. As Siemens and Roche uses streptavidin-biotin immobilizing system while Abbot uses a magnetic bead-based capture system, the abnormal results could be due to biotin interference.

Case 3: A 65-year-old lady, clinically asymptomatic was referred to us with Free T4 29.2 pmol/L (10.0 – 24.0 pmol/L) and TSH 1.59 mU/L (0.2 – 5.0 mu/L), 3 months after stopping amiodarone, which she took for 3 weeks for atrial fibrillation. This was thought to be due to amiodarone, owing to its long half-life of 58 days. We repeated thyroid function tests in 3 months from first clinical encounter i.e. 6 months after stopping amiodarone that showed Free T4 24.2pmol/L and TSH 2.30 mU/L and repeated further 3 months later that were normal, confirming amiodarone induced abnormal biochemical profile requiring no treatment.

Conclusion: Hyperthyroxinaemia with normal TSH need to be interpreted with caution as illustrated above. Some of them do not need treatment and inappropriate interpretation can potentially cause anxiety for the patient and harm due to unnecessary treatment.

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<![CDATA[MON-469 Rapidly Expanding Thyroid Goiter as the First Manifestation of Systemic Amyloidosis]]> https://www.researchpad.co/article/elastic_article_8731 INTRODUCTION

Amyloidosis is a condition manifesting with extracellular tissue deposition of fibrils of low molecular weight proteins. In Ig light chain amyloidosis (AL), the deposition of Ig light chains can cause organ dysfunction, and patients can have involvement of a range of organs including kidney (70%), liver (70%), heart (60%), peripheral nerves (20%), the tongue, skin, and the coagulation system (1). We describe a unique case of AL amyloidosis, which first presented with thyroid involvement.

CLINICAL CASE

A 78 year old female patient with hx of small lymphocytic lymphoma and normal thyroid function presented with an expanding symptomatic goiter and compressive symptoms (positive Pemberton sign) for which a total thyroidectomy was performed. Pathology showed Congo red-birefringent amyloid deposition. SPEP showed a small amount of M protein, with circulating monoclonal free lambda light chain on immunofixation. The free kappa lambda light chain ratio was low (0.04) with an elevated serum free lambda light chain (283.93). Mass spectrometry confirmed AL light chain amyloidosis - lambda type. A work up was initiated to assess other organ involvement. Echocardiogram showed mild thickening of left ventricle with a preserved EF and EKG showed low voltage in limb leads. Creatinine (1.05) was minimally elevated from baseline with minimal proteinuria (396 mg/24 hours). Alkaline phosphatase, APTT, and PT were normal. The patient described tongue enlargement and scalloping of the tongue from tooth impingement was seen. Biopsies of tongue and bone marrow also showed amyloidosis thereby securing the diagnosis of systemic amyloidosis, and chemotherapy was initiated.

CONCLUSION

This case illustrates the importance of considering amyloid goiter in the differential for a rapidly enlarging thyroid, even when there is no history of amyloidosis. Although extremely uncommon, a few case reports have described amyloid goiter. In our case, thyroid AL was the initial presentation of systemic amyloidosis. Because disease can be localized or systemic, work up should include an assessment for the presence of a monoclonal gammopathy and an assessment for amyloid mediated organ dysfunction. Tissue should be sent for amyloid typing – there are 35 different proteins known to form amyloid fibrils and prognosis and treatment depends on amyloid type (2). Typing using Liquid Chromatography-Tandem Mass Spectrometry, is the most sensitive and specific methodology, though, in experienced hands, typing by immune histochemistry is an option.

REFERENCES

1. Rajkumar, S.V., Dispenzieri, A. Clinical presentation, laboratory manifestations, and diagnosis of immunoglobulin light chain (AL) amyloidosis. Uptodate. 2019.

2. Winter, M., Tholey, A., Kristen, A., Röcken, C. MALDI Mass Spectrometry Imaging: A Novel Tool for the Identification and Classification of Amyloidosis. Proteomics 2017, 17, 1700236.

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<![CDATA[MON-478 Impaired Sensitivity to Thyroid Hormone - A Diagnostic and Therapeutic Challenge]]> https://www.researchpad.co/article/elastic_article_8690 Background: Impaired sensitivity to thyroid hormone refers to any process that negatively affects its action, including defects in its transport, metabolism and action on the receptor. Resistance to thyroid hormone due to beta-receptor mutations (RTH-beta) is the most common form of this entity and is characterized by reduced response of peripheral tissues to the action of thyroid hormone. The genetic variability of cofactors involved in the action of thyroid hormone explains the heterogeneity of resistance among affected individuals. Generally, patients with this disorder, have increased levels of free T4 and free T3 in association with normal or high TSH. Clinical case: 11-year-old boy, with personal history of Attention-deficit/hyperactivity disorder (ADHD). A pediatric endocrinology consultation was requested to evaluate abnormalities in his thyroid function tests. A few months earlier, his father was referred to endocrinology consultation because of thyroid function tests abnormalities: TSH - 3.01 μIU / mL (N: 0.35 - 4.94); Free T4 1.7 ng / dL (N: 0.7-1.48); Free T3 4.77 pg / mL (N: 1.71-3.71). Initially, two diagnostic hypotheses were considered: central hyperthyroidism or impaired sensitivity to thyroid hormone. The adult underwent pituitary magnetic resonance, which raised the hypothesis of a pituitary microadenoma, and TRH stimulation test, whose result was strongly suggestive of the second diagnostic possibility. A genetic study was requested and the presence of the c700 G> A variant (p. Ala 324 trh) in the THRB gene was identified, which confirmed the most likely hypothesis. At the time of the pediatric endocrinology consultation, the 11-year-old boy had the results of his lab tests: TSH - 6.67 μIU / mL (N: 0.35 - 5); T4L 2.27 ng / dL (N: 0.88-1.58); T3L 7.79 pg / mL (N: 2-4.20). Given his perfect height and weight evolution and the absence of symptoms suggestive of hypo or hyperthyroidism, it was decided not to start any medication, keeping only periodic surveillance. Conclusion: This case exemplifies unusual thyroid function tests. This discordance between serum thyroid hormone and TSH concentrations should raise the possibility of impaired sensitivity to thyroid hormone. In this condition, patients may present with symptoms of hypo or hyperthyroidism and the etiology of thyroid function tests abnormalities are not easily recognized. This can lead to misdiagnosis and consequently unnecessary treatment.

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<![CDATA[MON-471 The Broken Heart That Hid Behind the Goiter]]> https://www.researchpad.co/article/elastic_article_8688 Most goiters grow slowly over many years and are often asymptomatic. Although substernal goiters are estimated to represent between 5-24% of all mediastinal masses [1], a majority are benign. Symptoms may include neck fullness, nocturnal or positional dyspnea, or dysphagia due to tracheal and/or esophageal compression [2-3]. We present a case of a patient with new onset dyspnea that was initially attributed to a large intrathoracic goiter, but ultimately was found to be due to severe heart failure.

A 72-year-old man with a history of HTN, type 2 diabetes, and moderate aortic regurgitation presented to his primary care physician with exertional dyspnea, dry cough, and bilateral leg edema for 2 months. He was referred to pulmonology and a chest CT showed a large intrathoracic goiter, measuring 8.5 x 4.6 x 5.3 cm, extending from the left limb of the thyroid into the mediastinum with rightward tracheal and leftward aortic arch displacement. The patient had no prior history of thyroid disease, cancer, or neck radiation. He denied neck fullness, dysphagia, positional or nocturnal dyspnea, though his exertional dyspnea was progressive. Labs revealed that the patient was biochemically euthyroid. Due to concern for malignancy, the patient underwent a biopsy via EBUS/bronchoscopy, which was non-diagnostic. The case was ultimately discussed at cardiothoracic tumor board, and it was determined that since the mass had likely been present for several years and with the surgical risks being high, to continue monitoring with serial imaging.

At this point, the patient’s dyspnea and edema continued to worsen, and he was evaluated with an echocardiogram which showed a severe worsening of ejection fraction in just three months, from 53% to 5%, with global hypokinesis. He was started on diuretics and medical therapy with prominent improvement in his dyspnea. His cardiology team felt this acute decompensation was likely due to coronary artery disease and recommended left heart cardiac catheterization, however the patient declined.

Goiters tend to be asymptomatic and grow slowly over time. Given their intra-thoracic location and ability to prominently deviate the mediastinum, it can be tempting to attribute respiratory symptoms to large substernal goiters. However, when a patient develops acute symptoms, one must always rule out alternative diagnoses.

References

1. Priola AM, Priola SM, Cardinale L, Cataldi A, Fava C. The anterior mediastinum: diseases. Radiol Med. 2006;111(3):312

2. Katlic MR. Wang CA, Grillo HC. Substernal goiter. Ann thorac surg. 1985;39(4):391.

3. Benbakh M, Abou-elfadl M, Rouadi S, Abada RL, Roubal M, Mahtar M. Substernal goiter: experience with 50 cases. Euroepean annals of otorhinolaryngology, head and neck diseases. 2016-02-01, volume 133, issue 1, 19-22.

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<![CDATA[MON-463 Thyroid Abscess Due to Intravenous Drug Use: A Rare Cause of Thyroid Storm]]> https://www.researchpad.co/article/elastic_article_8672 Objective: Our objective is to discuss the clinical presentation, diagnosis and management of thyroid storm due to thyroid abscess.

Methods: We report a case of thyroid abscess due to intravenous drug use (IVDU) resulting in thyroid storm.

Results: A 28 year old female with history of IVDU and no known thyroid disease presented with neck pain and fever after injecting heroin into her neck 10 days prior. CT Neck showed an early bilateral thyroid abscess 3.0 cm on the left and 2.0 cm on the right, with heterogeneous enhancement in the rest of the thyroid concerning for thyroiditis. TSH 0.4 m[iU]/L (0.34–5.60 m[iU]/L). She was started on antibiotics but left AMA. She returned 9 days later with worsening neck swelling and pain. CT neck showed a multiloculated, bilateral thyroid abscess 8.6 cm on the left and 5.3 cm on the right. She suffered a cardiac arrest, was intubated, and resuscitated with defibrillation and epinephrine. WBC 25.9 K/mm3, ANC 9.8 K/mm3, TSH <0.01 m[iU]/L (0.34–5.60 m[iU]/L), fT4 4.25 ng/dL (0.89–1.76 ng/dL), T3 96.0 ng/dL (70–204 ng/dL), TSI <89 (<140%). Burch-Wartofsky score was 60. She was treated with propylthiouracil (PTU) and hydrocortisone. She developed transaminitis post-arrest due to shock liver, AST 2881 U/L (15–37 U/L), ALT 981 U/L (16–61 U/L) and PTU was discontinued. Two days later TSH <0.005 m[iU]/L (0.4–4.5 m[iU]/L), fT4 3.06 ng/dL (0.89–1.76 ng/dL), T3 62.0 ng/dL(60.0–181.0 ng/dL). Neck ultrasound showed enlarged, heterogeneous thyroid with numerous loculated fluid collections. Incision and drainage (I&D) drained 100 cc of pus and drains were left in situ. Cultures grew MRSA. Patient was treated with vancomycin, clindamycin, and metronidazole. Following I&D, thyroid function improved to normal and eventual hypothyroidism by postoperative day 8, fT4 0.59 ng/dL, T3 32.1 ng/dL, TSH 1.2 m[iU]/L. She was initiated on levothyroxine 50 mcg daily with follow up testing for possible resolution of thyroiditis-induced hypothyroidism.

Discussion: Thyroid abscess causing acute suppurative thyroiditis presenting as thyroid storm is rarely seen1. There are no reported cases of thyroid storm occurring as a complication of IVDU. Acute suppurative thyroiditis has been reported following MSSA bacteremia from a forearm abscess due to IVDU, TSH 0.02U/mL, fT4 3.89ng/dL, fT3 of 5.1pg/mL2. Presentation was consistent with thyrotoxicosis but not thyroid storm2. It is important to consider thyroid abscess as a rare cause of thyroid storm, in patients with risk factors such as IVDU. Management with antithyroid drugs (ATD), steroids, antibiotics, and I&D produced successful outcomes in this patient after cardiac arrest.

Conclusion: Thyroid abscess resulting in thyroiditis can be a rare cause of thyroid storm that resolves following I&D. Successful management includes use of antibiotics, steroids, and ATD for thyroid infection, thyroid inflammation and thyroid hormone levels.

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<![CDATA[MON-468 Hypoechoic Nodule Is Not Always the Bad Guy: Lessons Learned from a Patient with Subacute Painful Thyroiditis]]> https://www.researchpad.co/article/elastic_article_8548 Introduction: The diagnosis of subacute painful thyroiditis (SAT) is primarily based on clinical manifestations (thyroid tenderness and diffuse goiter). Suppressed TSH, elevated erythrocyte sedimentation rate (ESR) and low thyroid uptake help confirm the diagnosis. Thyroid ultrasonography and fine-needle aspiration biopsy (FNAB) are rarely necessitated. SAT produces a typical sonographic findings of ill-defined heterogeneously hypoechoic areas, which is difficult to differentiate from thyroid carcinoma. We herein report a patient with SAT who was initially diagnosed as malignancy. Case Presentation: A 36-year-old female had pain and swelling at the left thyroid gland for 3 weeks. A left thyroid nodule was diagnosed by her primary care physician. Ultrasonography revealed a poorly defined hypoechoic nodule measuring 2.5x1.1x1.5 cm at the mid pole of the left thyroid gland, for which biopsy was recommended. The nodule showed peripheral vascularity and no calcification. No suspicious cervical lymphadenopathy was detected. Histologic analysis from core biopsy found findings consistency with follicular neoplasm. Thyroid function tests were within normal range. She was treated with ibuprofen as management of thyroid pain and referred for surgery. However, the repeated ultrasonography was performed by endocrinologist in the next 2 weeks and found an interval reduction in size of hypoechoic lesion. FNAB was performed due to the risk of infiltrative malignancies. Cytologic analysis was compatible with SAT. ESR was slightly elevated. Surgery was cancelled and she was treated with ibuprofen. Two weeks later, she reported that the left thyroid pain and swelling had subsided. However, she developed thyroid pain associated with glandular tenderness and swelling of the right thyroid. On sonographic examination, the right lobe, which was previously normal was now similarly affected. Thyroid function showed thyrotoxicosis. The patient was given a further course of beta-blocker, ibuprofen and prednisolone for 2 weeks and recovered well. On follow-up at 2 months, the patient developed biochemical hypothyroidism and received levothyroxine replacement. The lesions in the thyroid gland were not visualized in the 6-month follow-up sonography. Conclusion: The ultrasonographic features of the thyroid during the acute stage of SAT may mimic thyroid carcinoma. Awareness of the sonographic findings and interval changes of SAT lesions may helpful for proper diagnosis and treatment of SAT.

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<![CDATA[MON-464 A Rare Case of Hypocalcemia-Induced Intractable Vomiting Requiring PEG Tube Placement]]> https://www.researchpad.co/article/elastic_article_7053 Introduction: Hypoparathyroidism is characterized by hypocalcemia and hyperphosphatemia secondary to inadequate PTH secretion. Clinical manifestations are carpopedal spasm, perioral paresthesia, and seizures. Herein, we present a case of hypoparathyroid-induced hypocalcemia requiring PEG tube placement.

Case Presentation: Patient is a 41-year-old female who presents with intractable nausea, continuous vomiting, abdominal pain, and perioral paresthesia for the past 4 days. Patient has a past medical history significant for hypoparathyroidism, severe hypocalcemia, hypomagnesemia, hyperphosphatemia, and iron deficiency anemia. Patient was diagnosed with hypoparathyroidism at the age of 16 when her son was born with congenital abnormalities due to severe maternal hypocalcemia. She has 4 children, 1 son passed away in infancy from severe hypocalcemia. Out of the remaining 3 children, 2 daughters have hypoparathyroidism. Patient has had multiple recurrent admissions for severe hypocalcemia presenting as angina, syncope, and left-sided weakness. Both cardiology work up and neurology workup have been negative. MRI of the brain shows basal ganglia calcifications. Labs are significant for corrected calcium 6.72 mg/dL (n 8 to 10 mg/dL), magnesium 1.4 mg/dL (n 1.7 to 2.2 mg/dL), phosphorus 7.4 mg/dL (n 2.4 to 4.5 mg/dL), Vitamin D 14.9 ng/mL (n 30 to 100 ng/mL), and PTH level 9.8 pg/mL (n 18.5 to 88 pg/mL). Prior ACTH stimulation test was within normal limits excluding adrenal insufficiency. EGD biopsy on prior admission was positive for H. Pylori, however patient left against medical advice and did not receive triple therapy. Patient was admitted for hypocalcemic crisis and placed on a calcium gluconate drip, oral calcium, magnesium, calcitriol, and Vitamin D, in addition to H. pylori triple therapy. During the hospitalization, she was unable to tolerate oral medications for greater than 2 weeks resulting in PEG placement. The patient’s electrolytes were successfully repleted via PEG tube and she was discharged.

Discussion: Spontaneous hypoparathyroidism is a rare metabolic disorder characterized by parathyroid glands that do not produce or secrete enough PTH to maintain normal levels of calcium and phosphorous in the blood. Though GI consequences such as steatorrhea may occur, to our knowledge, this is the first reported case of hypocalcemia-induced intractable vomiting requiring PEG tube. Before PEG placement, the patient had 12 admissions in 1 year. After PEG placement, the number dropped significantly to 4 admissions in 1 year. Due to the unique presentation of hypoparathyroid hypocalcemia, we would like to raise awareness regarding such a presentation which can be challenging for clinicians.

References: Abboud B, Daher R, Boujaoude J. Digestive manifestations of parathyroid disorders. World J Gastroenterol. 2011;17(36):4063-4066. doi:10.3748/wjg.v17.i36.4063.

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<![CDATA[MON-484 Thyroid Nodules: Not so Simple to Manage]]> https://www.researchpad.co/article/elastic_article_7013 Thyroid Nodules: Not So Simple to Manage

Thyroid nodules diagnosis and malignancy risk stratification remains a challenge for decision making between conservative vs invasive management. The development of the clinical guidelines provides alternatives for evaluation and management for thyroid nodules, but can be used for all patients?

A 43 y/o female without known past medical history is referred to the endocrine service by her primary care physician for evaluation of a thyroid nodule. She was presenting with 1 month history of mild discomfort on the neck and was evaluated with thyroid US that was relevant for multiple bilateral solid nodules measuring <1.0cm and a one spongiform measuring 1.7 x 1.2 x 1.3cm in the right lobe extending minimally to the capsule laterally and to the carotid artery wall. Patient denies cough, hoarseness, odynophagia, shortness of breath, family history of thyroid cancer or radiation exposure. On examination there were no goiter nor palpable thyroid nodules, as well as no clinical signs and symptoms of thyroid disease. Patient is clinically and biochemically euthyroid with a very low suspicion thyroid nodule (3% estimated malignancy risk). Despite nodule is below the 2.0cm cutoff point for fine needle aspiration biopsy (FNAB) according to American Association of Clinical Endocrinologist (AACE) and American Thyroid Association (ATA) guidelines, it was done based on additional suspicious sonographic features detect by the endocrinologist on evaluation of ultrasound images. FNAB was performed and reveals Atypia of undetermined significance/Follicular Lesion of undetermined significance (AUS/FLUS) Bethesda system category III with a risk of malignancy of 5–15%. Patient was reluctant to surgery given the very low risk nodule and biopsy results of AUS/FLUS. In order to further manage this patient with undetermined significance thyroid nodule, Gene Expression Classifier (GEC) Molecular Analysis (AFIRMA) was performed. AFIRMA test was done with a second FNAB that also reveals AUS/FLUS but was found positive for BRAFv600, Bethesda system category IV: Suspicious of Papillary Thyroid Carcinoma. BRAFv600 is the only mutation that have high specificity (99%) for papillary thyroid carcinoma and is associated with increased disease-specific mortality, aggressive histologic phenotypes, lymph node metastases, extrathyroidal extension and risk of recurrence. Based on this data patient now have 95% risk of malignancy and requires surgical therapy. Patient preferred total thyroidectomy over lobectomy; pathology results shows 2.0cm Papillary Thyroid Carcinoma Stage I (T1N0M0).

Despite very low risk nodule finding, malignancy was diagnosed. As depicted in this case, thyroid nodules aren’t so simple to manage, and their management should involve imaging and pathology findings along with clinical judgement and patient individualization in decision making process.

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<![CDATA[MON-458 Elevated Thyroglobulin Level in Benign Thyroid Nodule]]> https://www.researchpad.co/article/elastic_article_6960 Background: Elevated thyroglobulin levels are most commonly associated with differentiated thyroid carcinoma and these levels are often used to monitor for disease recurrence. Thyroglobulin antibody levels can be elevated in both Hashimoto’s Thyroiditis and Graves’ Disease and these antibodies can interfere with thyroglobulin levels as detailed by Spencer, Wang (1). With benign thyroid nodules, there is limited research regarding thyroglobulin levels as studied in Chinnappa, et al (2).

Clinical Case: A 31-year woman presented with a palpable thyroid nodule and dysphagia. Her primary care physician ordered thyroid labs including normal TSH (1.3 mIU/L, n0.4-4 mIU/L), normal thyroid peroxidase antibody (56 units, n<250units), normal thyroglobulin antibody level (<1 IU/mL, n<1 IU/mL), and elevated thyroglobulin level (469.1 ng/mL, n2.8-40.9 ng/mL). Her thyroglobulin levels remained elevated on repeat testing (224.4 ng/mL, n2.8-40.9) one month later. In addition, her thyroglobulin lab studies were repeated with HAMA treatment and remained elevated (277.7 ng/mL, n2.8-40.9). Office ultrasound showed longest dimension of nodule to be 5 cm and patient received FNA biopsy. Biopsy results were reported as a benign nodule and it was recommended to follow-up in 12 months. Six months later the patient reported having increasing dysphagia. She underwent Barium swallow which showed no abnormalities. She had a growth increase of 35% on repeat imaging along with increasing neck pressure and discomfort and was referred to an ENT for surgery. Final pathology after left thyroid and isthmus thyroidectomy was reported as “Multinodular hyperplasia with background thyroid parenchyma histologically unremarkable. Negative for malignancy.” Thyroglobulin levels subsequently returned to within the normal range and the patient’s dysphagia resolved.

Conclusion: Thyroglobulin levels can be markedly elevated with benign thyroid nodules, which can mislead physicians and increase concern for thyroid cancer.

References: (1) Spencer, CA, Wang, CC. Thyroglobulin measurement. Techniques, clinical benefits, and pitfalls. Endocrinol Metab Clin North Am. 1995 Dec; 24(4): 841-63.

(2) Chinnappa, P, Taguba, L, Arciaga, R, Faiman, C, Siperstein, A, Mehta, AE, Reddy SK, Nasr, C, Gupta MK. Detection of thyrotropin-receptor messenger ribonucleic acid (mRNA) and thyroglobulin mRNA transcripts in peripheral blood of patients with thyroid disease: sensitive and specific markers for thyroid cancer. J Clin Endocrinol Metab. 2004 Aug;89(8):3705-9.

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<![CDATA[MON-470 Biotin Masquerading as Subclinical Hyperthyroidism]]> https://www.researchpad.co/article/elastic_article_6599 Introduction: Thyroid conditions are among the most common endocrine disorders. Diagnosis is dependent on interpretation of laboratory tests. The challenge comes when the clinical picture is discordant with laboratory results.

Case Report: Patient is a 53-year-old male with history of cardiac transplantation, type 2 diabetes mellitus, history of amiodarone-induced hyperthyroidism. He was noted to have labs indicative of hyperthyroidism, while taking amiodarone, in 2016-2017, which was treated with methimazole. He was then noted to have abnormal thyroid function tests with low TSH to 0.3 IU/L, normal T3 and normal T4 levels. Thyroid stimulating immunoglobulin had been checked multiple times, and was normal, which is inconsistent with Graves’ disease. Prior radioactive iodine uptake scan, while off amiodarone, was noted to be normal. He was also scheduled for thyroidectomy at another hospital, which was cancelled due to normalization of thyroid function tests. Consultation was received for suppressed TSH to 0.323 IU/L, without symptoms of hyperthyroidism. He had been taking biotin during this time, which he subsequently stopped taking. Repeat TSH following discontinuation of biotin, was within normal range, most recent TSH 2.48 IU/L, free T4 1.03 ng/dL, free T3 2.7 pg/mL.

Discussion: Thyroid function tests are commonly ordered. Interpretation of these tests relies on the provider’s understanding of thyroid physiology in addition to interferences with medications and other conditions. High doses of biotin, which people take as supplements for multiple sclerosis, or metabolic disorders, or for healthy nails and hair, can cause thyroid function test abnormalities. Streptavidin and biotin are used in some immunoassay platforms to capture antigens (TSH, free T4) or antibodies. High levels of serum biotin can inhibit the formation of T4 antibody complex, which results in a falsely high free T4 result.

Conclusion: Thyroid Function tests should be interpreted very cautiously, especially in the setting of discordant clinical findings. Prior to ordering these tests, should attempt to obtain a detailed history of medications including over-the-counter supplements, which are commonly not reported during medication history.

References:Elston, Marianne S., et al. “Factitious Graves’ Disease Due to Biotin Immunoassay Interference—A Case and Review of the Literature.” The Journal of Clinical Endocrinology & Metabolism, vol. 101, no. 9, 30 June 2016, pp. 3251-3255., doi:10.1210/jc.2016-1971. Koehler, Viktoria F., et al. “Fake News? Biotin Interference in Thyroid Immunoassays.” Clinica Chimica Acta, vol. 484, 30 May 2018, pp. 320-322., doi:10.1016/j.cca.2018.05.053. Soh, Shui-Boon, and Tar-Choon Aw. “Laboratory Testing in Thyroid Conditions - Pitfalls and Clinical Utility.” Annals of Laboratory Medicine, vol. 39, no. 1, 13 Jan. 2019, pp. 3-14., doi:10.3343/alm.2019.39.1.3.

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<![CDATA[MON-485 Thyroid Abscess in a Healthy 22-Year Old Female]]> https://www.researchpad.co/article/elastic_article_6361 Background: Thyroid abscess is a rare pathology, exhibiting an incidence of less than 1% of all thyroid diseases. The thyroid is highly resilient against infections. Those who do experience thyroid abscesses are commonly immunocompromised. We illustrate a case of a thyroid abscess in a young, healthy patient.

Clinical Case: A previously healthy 22-year-old woman presented to the emergency department complaining of a sore throat, fever, nausea, and body aches. On exam, the patient was febrile, but had no obvious cervical lymphadenopathy, masses, or oropharyngeal lesions/growths. Initial labs showed leukocytosis to 13.5 k/ul with left-shift. The patient was diagnosed with acute pharyngitis, and was discharged on oral steroids and antibiotics for an incidental urinary tract infection.

After some improvement, the patient returned to the ED 14 days later with a worsening odynophagia, dysphagia, and hematemesis. The patient was afebrile, but had neck swelling and possible thyromegaly. Lab results showed leukocytosis to 17.3 k/ul, and CT of the neck identified a 3.1cm x 3.3cm x 4.4c heterogeneous cystic/solid mass that nearly completely replaced the normal right thyroid lobe parenchyma and extended to the isthmus. Right-sided lymphadenopathy was also present. Initial evaluation suggested thyroid carcinoma. The patient was re-initiated on steroids due previous improvement, and was referred to a tertiary academic medical center for biopsy and further evaluation. 2 days later, the patient returned to the ED for worsening symptoms. However, she was discharged to home with no further management.

At her endocrine surgery consultation visit, the patient reported worsening pain, inability to move her neck, inability to eat or drink, inability to lie flat, and new-onset sialorrhea and voice changes. A bedside ultrasound was performed with findings suggestive of an abscess. An in-office fine-needle aspiration produced purulent fluid, which relieved some of the patient’s compressive symptoms. Cytology showed inflammatory cells (mostly neutrophils) and numerous bacteria. The patient was emergently taken to the operating room for neck exploration, hemithyroidectomy, and incision/drainage of a suspected thyroid abscess. A drain was placed and removed POD 2 after minimal output.

The patient was discharged on oral antibiotics. 1-week post-operatively, the patient returned to the ED due to reaccumulation of the abscess. This was successfully treated with IR placement of a drain. The drain was removed 2-weeks post-operatively, and the patient is doing well.

Conclusion: Thyroid abscesses are rare but possible in young and immune-competent patients. While the imaging findings can point towards a more common diagnosis, such as thyroid carcinoma, avoiding anchoring bias is important. Imaging data should be considered in the context of the clinical picture to avoid the possibility of misdiagnosis.

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<![CDATA[MON-472 A Case of Resistance to Thyroid Hormone with Concurrent Hashimoto’s Thyroiditis and Post-Surgical Hypothyroidism]]> https://www.researchpad.co/article/elastic_article_6294 Introduction: Resistance to thyroid hormone (RTH) is a rare defect that results in impaired sensitivity to thyroid hormone. While most commonly caused by mutations in the thyroid hormone receptor beta (THRβ) gene, in 15% of patients with the RTH phenotype, no mutation is identified.1 This entity is known as non-thyroid hormone receptor RTH (nonTR-RTH). Patients with RTH have an increased risk of autoimmune thyroid disease with a reported odds ratio of 2.36.2 Hashimoto’s thyroiditis or other etiologies of hypothyroidism add a layer of complexity to RTH as such individuals may require high doses of levothyroxine to overcome hormone resistance.

Clinical Case: A 36-year-old male was referred for abnormal thyroid function tests. He denied symptoms of thyroid dysfunction. Physical examination was notable for a goiter. Weight was 83 kg. Initial labs revealed TSH 6.8 mcIU/mL (0.3-4.7 mcIU/mL), free T4 2.0 ng/dL (0.8-1.7 ng/dL), free T3 491 pg/dL (222-383 pg/dL), and thyroid peroxidase antibody >600 IU/mL (≤20 IU/mL). Additional work-up demonstrated elevated free T4 by equilibrium dialysis 2.5ng/dL (0.9-2.2 ng/dL) and elevated TSH with HAMA treatment 5.96 mIU/L (0.40-4.50 mIU/L), thereby ruling out familial dysalbuminemic hyperthyroxinemia and HAMA interference. Alpha-subunit of 0.30 ng/mL (<0.55 ng/mL) and normal pituitary MRI did not support a TSH-secreting adenoma. Quest Diagnostics RTH Gene Sequencing was negative for a mutation in the THRβ gene. The patient was subsequently diagnosed with nonTR-RTH. Thyroid ultrasound showed multiple thyroid nodules, including a 1.8 cm hypoechoic, complex nodule in the left inferior gland and a 1.7 cm isoechoic nodule in the right inferior gland. Fine needle aspiration of the left nodule was suspicious for papillary thyroid carcinoma and the right nodule showed lymphocytic thyroiditis. The patient underwent total thyroidectomy and pathology demonstrated a benign left nodule and an incidental 0.3 cm right papillary thyroid carcinoma. The patient started levothyroxine 150 mcg daily (1.8 mcg/kg) post-operatively with subsequent TSH of 18.1 mcIU/mL. His dose was increased to 200 mcg daily (2.4 mcg/kg) and TSH was still elevated at 11.7 mcIU/mL. His levothyroxine dose was subsequently increased to 250 mcg daily (3 mcg/kg) and TSH is outstanding.

Conclusions: This case highlights the diagnostic challenge in nonTR-RTH. It also demonstrates the complex management of patients with RTH and concurrent hypothyroidism. Such patients need close monitoring and aggressive titration of levothyroxine to achieve desired hormone levels.

1. Dumitrescu AM, Refetoff S. The syndromes of reduced sensitivity to thyroid hormone. Biochim Biophys Acta 2013;1830:3987-4003.

2. Barkoff MS, Kocherginsky M, Anselmo J, Weiss RE, Refetoff S. Autoimmunity in patients with resistance to thyroid hormone. J Clin Endocrinol Metab 2010;95:3189-93.

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<![CDATA[MON-483 Familial Dysalbuminemic Hyperthyroxinemia with False Hypercortisolemia]]> https://www.researchpad.co/article/N65c7618f-e694-48da-b42f-a3c942df51d7 <![CDATA[MON-479 Acute Thyroid Edema: A Rare Complication of Thyroid Fine Needle Aspiration]]> https://www.researchpad.co/article/Ndfaa0fa6-ef44-46ee-b74f-8cfc4d860b49 <![CDATA[MON-465 Novel Thyroid Hormone β Mutation L266s Causes Atrial Fibrillation & Cerebral Infarction]]> https://www.researchpad.co/article/N394792f6-e554-4faa-afff-65a47a9bb306 <![CDATA[MON-482 Thyroid Tuberculosis - An Unlikely Diagnosis]]> https://www.researchpad.co/article/Nee0f0fdb-1edd-4a83-b184-8ca5408dc040 <![CDATA[MON-461 A Rare Case of Thyroglobulin Deficiency with Ectopic Thyroid Tissue]]> https://www.researchpad.co/article/N23615085-b208-42d5-8cc9-9c8e9bf54444

Abstract

Background: The production of thyroglobulin (TG) is initiated by TSH binding to the TSH receptor leading to the transcription and production of TG protein. TG protein then gets transported to the lumen of the follicular cell where its tyrosine amino acids get iodinated and coupled to form T3 and T4. TG deficiency is a rare autosomal recessive genetic condition characterized by congenital thyroid goiter, increased thyroid uptake and primary hypothyroidism.

Clinical Case: A 21 year old South Asian female with a history of TG deficiency, hypothyroidism, and thyroid goiter status post thyroidectomy presented with a right sided neck mass. She was diagnosed hypothyroidism with a goiter at the age of five. Levothyroxine replacement was initiated and she had normal growth and development. At the age of ten upon transferring care to our health network, there was concern for enlargement of the goiter. Labs showed TSH of 2.85 uIU/mL (normal: 0.36-3.74 ulU/mL), thyroid binding globulin of 18.2 ug/mL (normal: 13-30 ug/mL), TG antibody less than 20 IU/mL (normal: less than 40 lU/mL) and TG level less than 0.2 ng/mL (normal: less than 55 ng/mL). Thyroid uptake and scan showed overall increased uptake. Genetic studies revealed homozygous mutation of thyroglobulin deficiency. Further history obtained confirmed patient’s parents were first cousins with heterozygous thyroglobulin mutations. Due to enlarging multinodular goiter with thyroid gland measuring 6.2 cm x 4 cm on the right and 6.2 x 3.6 cm on the left, total thyroidectomy was completed in 2012. Pathology showed benign thyroid tissue. In May 2019 the patient skipped levothyroxine replacement due to lapse in prescription refill and TSH increased to 28 ulU/mL. Around that time, she noticed an enlarging right sided neck mass. MRI of the neck showed an enhancing mass posterior to the submandibular gland measuring 1.6 x 1.4 cm. Fine needle aspiration in August 2019, showed a mixed population of lymphocytes and few benign appearing glandular cells. Pathology obtained after resection of the right neck mass in September 2019 revealed benign thyroid tissue with no lymphoid tissue, staining positive for TTF-1 and PAX-8.

Conclusion: TG deficiency has an incidence of 1:100,000 live births and is more common in cases of genetic consanguinity. There have been over fifty mutations of varying penetrance identified leading to differing consequences in TG production and processing. These mutations can cause structural changes in the TG protein, decreased tyrosine residue on TG leading to poor iodination and ineffective TG transport within the follicular cell. We propose that the right sided neck mass was regrowth of residual thyroid tissue due to the stimulatory effect of TSH after missed doses of levothyroxine caused TSH elevation. Our case is the first of TG deficiency wherein the patient developed ectopic thyroid tissue proliferation after a period of thyroid hormone deficiency.

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<![CDATA[MON-475 Discrepant Thyroid Function Tests in Adenocarcinoma-Is This a True Thyroid Disorder?]]> https://www.researchpad.co/article/Ne6d0192d-6db1-462a-aa04-5529a65a81ed <![CDATA[MON-460 An Extremely Rare Case of Urothelial Carcinoma Metastasizing to the Thyroid Gland]]> https://www.researchpad.co/article/N2fd05ba7-6c58-4ce8-a053-fb4902c6afd4