ResearchPad - thyroid-cancer-case-reports-ii https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[MON-450 Prophylactic Thyroidectomy in a Patient with Codon 891 Mutation of the RET Proto-Oncogene]]> https://www.researchpad.co/article/elastic_article_8650 Background: Medullary thyroid cancer (MTC) is a neuroendocrine tumor of the parafollicular or C cells of the thyroid gland, accounting for 1-2% of thyroid cancers in the United States. About 25% MTCs are familial as a part of the MEN2 syndrome or familial MTC (FMTC). Germline mutations in codon 891 are predominantly associated with FMTC. Case: 65-year-old Caucasian male was referred to the Endocrinology clinic after bilateral thyroid nodules were found on thyroid US. The patient had requested an ultrasound of his thyroid after his brother was diagnosed with MTC following fine-needle aspiration for an incidental thyroid nodule prompting total thyroidectomy and genetic testing. The patient’s brother was found to be heterozygous for RET mutation (c.2617T>G;pSer891Ala). This resulted in screening of the other siblings including this patient, also found to be heterozygous for this mutation. Both parents were deceased, and their clinical history is not known. Only one of the remaining two siblings had genetic testing; one brother refused testing for the mutation and one sister was positive for the mutation but had no thyroid nodules on ultrasound. She underwent prophylactic thyroidectomy. Neither the patient, nor his siblings, have any progeny. The patient screened negative for primary hyperparathyroidism and pheochromocytoma. Calcitonin (739, normal </=14.3 pg/mL)and CEA levels (31.7, 0-3.0 ng/mL) were elevated. Thyroid ultrasound (US) showed two solid hypoechoic nodules with lobulated margins and internal coarse calcifications in the right and two in the left thyroid lobe; 1.5 cm and 1.2 cm in maximum diameter, and 1.2 cm and 3 mm in maximum diameter, respectively. Based on elevated calcitonin and CEA levels, known RET mutation and evidence for thyroid nodules, we recommended a total thyroidectomy and central neck dissection. Pathology revealed multifocal, bilateral medullary carcinoma (largest focus of 1.5 cm), with 4/4 lymph nodes positive for metastasis. This was classified as mpT1bN1aM0 (Stage III). Patient was started on levothyroxine with plans to repeat calcitonin and CEA levels and neck ultrasound, 3 months following surgery. CT chest, abdomen and pelvis did not reveal any distant metastasis. Conclusion: Inherited MTCs are rare. Early diagnoses by screening of at-risk family members in MEN2 kindreds is important because MTC can be life-threatening and can be cured and prevented by early thyroidectomy. While our suspicion for FMTC in this patient and his siblings is high, FMTC is now considered a variant of MEN2A and ongoing screening for pheochromocytoma and primary hyperparathyroidism is recommended.

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<![CDATA[MON-435 Hashimoto Thyroiditis and Goiter: Never Cease Follow-Up]]> https://www.researchpad.co/article/elastic_article_8555 Background

Hashimoto thyroiditis (HT) is the most common cause of hypothyroidism in iodine-sufficient areas. Its incidence is estimated to be 3.5 per 1000 per year in women and 0.8 per 1000 per year in men (3). Primary thyroid lymphoma (PTL) is a rare complication of HT, but often forgotten. Regular follow-up and high clinical suspicion is needed to diagnose this complication early. We present a patient who developed PTL as a complication of HT after 10 years of diagnosis of HT and goiter.

Clinical case

A 70-year-old male with history of hypertension and obstructive sleep apnea followed up in the endocrine clinic for the last 10 years for Hashimoto thyroiditis and stable goiter presented with a sudden enlargement of right neck mass. In 2008 he was incidentally diagnosed with HT. In 2010 the patient returned with a neck swelling and further investigation revealed a cold nodule in the right lobe. The patient underwent aspiration biopsy with repeat finding of HT, and was followed up yearly with thyroid ultrasound and TSH. In 2014 due to concern in the echotexture of thyroid on ultrasound, he had a biopsy of the right thyroid nodule with findings again consistent with HT. No significant changes were noted on yearly follow-up ultrasound until March 2019. He presented 5 months later with a large mass on the right side of his neck. Ultrasound showed enlarged and confluent lymph nodes anterior to the enlarged right thyroid gland. Further CT evaluation showed a large right neck mass measuring 5.2 x 7.5 x 12 cm extending from the right thyroid lobe to the level of C1. The mass crossed the midline posteriorly. Fine needle aspiration was positive for malignant cells. A core biopsy confirmed diffuse large B-cell lymphoma. The patient had tests for staging, including bone marrow biopsy, and was found to be stage II E diffuse large B-cell lymphoma involving the thyroid. Subsequently, the patient was started on chemotherapy with RCHOP(Rituximab, Cyclophosphamide,Doxorubicin,Vincristine,Prednisolone).

Conclusion

Although Primary thyroid lymphoma (PTL) is a rare condition, it should always be considered in the differential diagnosis of a rapidly growing goiter or thyroid nodule. Its incidence is 2 per million, with nearly all cases the non-Hodgkin’s type. PTL accounts for only 0.5–5% of all thyroid malignancies and 1% to 7% of all extranodal lymphomas. The prevalence of Hashimoto thyroiditis in patients with PTL is highly variable, but patients with HT have a 40- to 80-fold increased risk of developing PTL. A rapidly enlarging neck mass with or without compressive symptoms is the common presentation of PTL. Most common histotype is diffuse large B cell lymphoma which accounts for 50% to 70% of cases. High clinical suspicion and awareness among physicians is needed to diagnose PTL early. The main treatment is chemotherapy. Surgical interventions are needed to relieve pressure symptoms. The prognosis of PTL is generally excellent.

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<![CDATA[MON-434 Encapsulated Follicular-Variant of Micropapillary Carcinoma Presenting with Distant Bony Metastasis]]> https://www.researchpad.co/article/elastic_article_7046 INTRODUCTION The incidence of thyroid cancer has risen steadily over the last decades, in part due to increasing diagnosis of apparently low-risk well-differentiated cancers. The outcomes of well-differentiated thyroid cancers, including follicular variant papillary thyroid carcinoma (PTC), are believed to be quite favorable, with a largely indolent benign course. We examine an encapsulated follicular-variant of micropapillary carcinoma presenting with distant bony metastasis. CASE 55-year-old lady presented to clinic after biopsy of iliac crest (IC) mass revealed thyroid tissue. One year prior she started having dull pain at right hip, attributed to increased physical activity. She noticed a tender “lump” on her right hip. CT revealed destructive right iliac 8 cm mass with extraosseous soft tissue component, central necrosis, and eccentric calcifications; and right ovarian cyst. Right IC biopsy was consistent with thyroid tissue with positive Thyroglobulin and TTF-1 immunostains. Physical exam was normal, except for mild tachycardia, hypertension, right flank large rounded mass fixed to IC, tender to palpation without erythema or warmth on overlying skin. Thyroid ultrasound showed normal thyroid gland except 5.58 x 6.22 x 7.76 mm left lobe nodule without increased vascularity but with coarse peripheral calcification. FNA was unsatisfactory. Thyroid function tests revealed undetectable TSH, elevated FT4, FT3, and markedly elevated thyroglobulin and TSI. PET/CT scan showed focal area of mild FDG avidity, corresponding to the right iliac crest mass, without additional areas of FDG avidity suggestive of metastatic disease or primary neoplastic process. Three weeks after presentation, patient began having symptoms of hyperthyroidism. As FT4 and FT3 continued to rise, she was started on propranolol and methimazole. Due to inadequate response, methimazole was switched to high dose propylthiouracil with mild improvement. Thyroid uptake and scan and SPECT-CT revealed increased thyroid uptake and thyromegaly consistent with Graves’ disease and redemonstrated large right IC lesion with increased uptake in the periphery and central photopenia, suggesting metastatic thyroid malignancy. Pathology from total thyroidectomy reported encapsulated follicular variant of PTC, confined to the left lobe of the thyroid, without extrathyroidal extension, greatest tumor dimension 0.6cm. As metastasis to the IC were unlikely to have originated from this small encapsulated thyroid cancer, it was recommended to proceed with right oophorectomy for suspected malignant struma ovarii and IC lesion debulking. Surgical pathology revealed right ovary and fallopian tube without pathologic changes or features of teratoma and tissue from right iliac mass consistent with PTC. Patient is off all antithyroid medications and remains biochemically euthyroid, awaiting radioactive iodine therapy.

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<![CDATA[MON-440 Unusual Case of Metastatic Struma Ovarii Diagnosed at the Time of Hysterectomy]]> https://www.researchpad.co/article/elastic_article_6998 Introduction: Struma ovarii is rare ovarian teratoma composed of more than 50% mature thyroid tissue, which can rarely transform to malignancy. There are fewer than 200 cases reported and no established treatment approach. We present a case of metastatic malignant struma ovarii. Case Presentation: A 41 year old female was diagnosed with metastatic papillary thyroid carcinoma (PTC) after it was found on uterine histopathology. History was notable for remote left ovarian cystectomy of a mature teratoma with prominent thyroid component. She had no personal or family history of craniocervical radiation or thyroid cancer. Eight years later, she had a total hysterectomy for menorrhagia. Pathology showed subcentimeter serosal deposits of follicular variant PTC, staining positive for thyroglobulin, CK19, and HBME1. Endometrial and cervical pathology were normal; the myometrium had many leiomyomata. Post-hysterectomy TSH was 2.3 (0.34 - 5.66 µIU/mL), and thyroglobulin 44.3 (<=33.0 ng/mL). Thyroid ultrasound showed a 7 mm isoechoic nodule without lymphadenopathy. Whole body PET/CT showed multiple hypermetabolic masses in the pelvic peritoneum and liver. The right ovary had many cystic lesions and was enlarged to 5.3 x 4.5 cm. She underwent partial hepatectomy, oophorectomy, salpingectomy, and omental resection with no residual disease. Pathology showed follicular variant PTC in both ovaries, peritoneum, colonic mesentery, and omentum. Thyroglobulin fell to 6.9 ng/mL 3 weeks later. A 0.2 cm focus of follicular variant PTC with capsular invasion was found on pathology after total thyroidectomy. She underwent radioiodine ablation with 150 mCi. Postablative scan showed residual activity in the thyroid bed and right hemipelvis, but no new foci of activity. CT abdomen showed resolution of perihepatic lesions and thyroglobulin declined further to 0.5 ng/mL. Discussion: A low risk of recurrence (7.5%) has been reported in patients with malignant struma ovarii, with survival rates of 96.7% at 5 years and 84.9% at 20 years, despite a variety of surgical and adjuvant management strategies. Unilateral cystectomy, unilateral salpingo-oophorectomy, or total abdominal hysterectomy and bilateral salpingo-oophorectomy may be sufficient for patients with well differentiated thyroid cancer arising in struma ovarii without metastases. Thyroid ultrasound should be performed to exclude primary thyroid malignancy. Patients with distant metastases may benefit from aggressive treatment including resection of gross abdominal and pelvic disease and total thyroidectomy to facilitate radioactive iodine ablation and surveillance for recurrence. Conclusion: Due to its rarity, there is no consensus on optimal treatment of malignant struma ovarii. More research in this field is warranted.

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<![CDATA[MON-443 SPECT/CT Localization of Incidental Diverticular Bleed After Radioiodine (i<sup>131</sup>) Therapy for Metastatic Thyroid Cancer]]> https://www.researchpad.co/article/elastic_article_6882 Background: Radioiodine therapy for patients with metastatic papillary and follicular thyroid cancer status post total thyroidectomy improves overall survival and is standard of care. Physiologic and pathologic biodistribution of I131 is dependent on tissue sodium iodine symporter expression with nonspecific radioiodine distribution seen secondary to physiologic routes of excretion.

Clinical Case: Whole body scintigraphy (WBS) was performed seven days after I131 therapy in a 37-year-old male treated for metastatic papillary thyroid cancer with extension to a thyroglossal duct cyst at the time of surgery. His post-procedural course was uncomplicated with the exception of self-limited hematochezia six days after ablation. WBS images demonstrated a focus more superiorly in the neck concordant with metastatic thyroglossal duct cyst involvement. Activity was also present in the small and large bowel distribution reflecting normal routes of radioiodine excretion. WBS images depicted a discrete focus of radioiodine activity in the right lower quadrant, which SPECT/CT further localizes as activity in the sigmoid colon. Non-contrast CT images demonstrate an associated linear pattern of hyperdense hyperattenuation in the colonic lumen consistent with fresh blood. It is well established that the physiologic and pathologic biodistribution of I131 is dependent on tissue sodium-iodine symporter expression with additional distribution secondary to normal routes of excretion. Nonspecific radioiodine localization has been described at sites of inflammation secondary to vasodilation and increased vascular permeability resulting in leakage and accumulation in tissues. Sodium-iodine expression is found in many tissues, including salivary glands, lactating mammary glands, gastric mucosa, thymus, and small bowel; however, they are not expressed in the colon, nasopharyngeal mucosa, or orbital fibroblasts. I131 localization has been previously described within numerous body diverticula, such as Zenker’s and Meckel’s diverticula; however, radioiodine activity in association with an acute colonic diverticular bleed has not been reported.

Conclusion: We propose that the isolated focus of radioiodine activity in the sigmoid colon associated with transient self-limited bleed could be either related to preexisting diverticulitis leading to I131 accumulation secondary to hyperemia, increased vascular capillary permeability, and subsequent aggravation of colonic mucosa resulting in a transient bleed or due to incidental nonspecific pooling of radioiodine in a colonic diverticulum resulting in secondary mucosal irritation with subsequent minor bleeding. To our knowledge this is the first reported case of SPECT/CT localization of radioiodine to an isolated colonic diverticular bleed in a patient status post I131 therapy for metastatic papillary thyroid cancer.

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<![CDATA[MON-437 False Positive I-131 Uptake]]> https://www.researchpad.co/article/elastic_article_6586 Background

Iodine has high specificity for thyroid tissue hence it plays very important role is management for differentiated thyroid cancer. Despite its high specificity and sensitivity, false-positive I-131 uptake could be seen on whole body scan (WBS).

We are presenting a case of false positive intense uptake in lung due to bronchiectasis.

Clinical case

Patient is a 78-year-old Asian female who initially present with left sided 5.8 cm thyroid nodule. The fine needle aspiration was performed, and the cytology came back as Bethesda category III. Per our institute protocol a molecular mutation panel was sent, which came back with NRAS mutation.

She underwent total thyroidectomy and the histology showed 6.2 cm Follicular carcinoma with extensive angioinvasion, oncocyte type. She received adjuvant 165.2 mci of RAI. Per protocol she had a one-week I-131whole body scan.

There was intense abnormal uptake in left mid and upper chest. The stimulate thyroglobulin with a TSH of >100mcIU/ml was only 0.17 ng/dl with Tab negative.

Patient subsequently had a PET CT which showed a faint diffuse FDG activity noted in the cystic bronchiectasis predominantly in the left apex, lingula, and right middle lobe. Patient informed us that she has history of pulmonary tuberculosis in 1970’s for which she was successfully treated in her home country. We had 10-year-old chest X-ray which showed stable cystic bronchiectasis lesion in the region of intense uptake.

Discussion

Although I131 whole body scan has high specificity and sensitivity but physician should be aware of potential false positive uptake to avoid unnecessary intervention. In a retrospective evaluation i the most common non-thyroid conditions included were bronchiectasis, lung infection, subcutaneous injection into gluteal fatty tissue, aortic calcification, benign bone cyst, vertebral hemangioma, recent nonthyroidal surgical procedure site, rotator cuff injury, mature cystic teratoma and ovarian follicle cyst). The accumulation of the bronchial secretion is the proposed mechanism of the high false positive uptake in bronchiectasis.

Endnotes

i Mol Imaging Radionucl Ther 2018; 27:99–106 DOI:10.4274/mirt.37450

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<![CDATA[MON-453 Dramatic Clinical Response to Lenvatinib in a Pediatric Patient with Advanced Metastatic Papillary Thyroid Carcinoma]]> https://www.researchpad.co/article/elastic_article_6450 Introduction: Papillary thyroid cancer (PTC) is the most common thyroid tumor in childhood. Most patients are referred with locally advanced and/or distant disease at the time of diagnosis. Whenever possible, these patients should be offered total thyroidectomy and radioiodine remnant ablation; however, this approach is not always feasible, rendering these tumors unresectable. These critical cases could benefit from neoadjuvant treatment with multikinase inhibitors (MKI) so that standard treatment can be performed. Lenvatinib is an MKI recently approved in many countries throughout the world for the treatment of radioiodine refractory adult differentiated thyroid cancer. Only few pediatric cases have been reported. Case report: A 10-year-old female patient with locally advanced PTC and metastasis to the lungs, who required 3 liters of oxygen due to respiratory failure caused by bilateral miliary lung disease, mistakenly treated as tuberculosis two months previously and referred to our Hospital. A large thyroid mass adhered to deep tissues was confirmed on CT scan, showing a large heterogeneous neck mass with multiple microcalcifications associated with multiple lymph nodes. Both lungs had multiple micro-nodular disease with interstitial involvement. Total thyroidectomy together with lymph-node dissection was planned, but extensive local infiltration made the lesion unresectable and surgery was limited to a thyroid biopsy. The patient required respiratory assistance. Histopathology confirmed the presence of a PTC (diffuse sclerosing variant) with a RET-PTC3 oncogene rearrangement. Eight days after surgery the patient was critical and we decided to indicate the compassionate use of Lenvatinib. The patient was started on oral lenvatinib at a dose of 14 mg daily (14 mg/m/day). Three days later, she clinically improved and nine days post-lenvatinib initiation, the patient was discharged from hospital without need for oxygen therapy. Lab studies showed a rise in thyroglobulin levels in the first month of treatment followed by a significant drop. All Lung Function Test parameters significantly improved. The patient initially had severe restrictive breathing and due to the resting dyspnea with hypoxemia she could not perform the walking test. Two months after treatment onset she could walk 360 meters in six minutes with 96% oxygen saturation. After 4 months on Lenvatinib, imaging studies showed a stable thyroid mass while the pulmonary nodules appeared stable to slightly smaller without evidence of new or progressive disease. Conclusion: On lenvatinib treatment, our patient showed significant clinical improvement, arrest of disease progression, and stable disease on imaging studies. This case shows that lenvatinib may be a beneficial option for children with advanced PTC not amenable to surgery/RAI treatment and may be used as a bridge to these first-line therapies.

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<![CDATA[MON-449 Thyroid Microcarcinoma Histopathology Relevance]]> https://www.researchpad.co/article/elastic_article_6309 INTRODUCTION: Thyroid carcinoma is the most common endocrine neoplasia. The predominant histological variant is the papillary subtype. Tumors with 1 centimeter diameter or less are defined as papillary thyroid microcarcinoma (PTMC). The clinical diagnosis of PTMC is challenging. The evaluation of the gland includes mostly image methods and fine-needle aspiration (FNA). Nevertheless, the sensibility of these techniques, when compared to total thyroid histology, is less than desired. AIM OF THE STUDY: Recognize the real prevalence of papillary thyroid microcarcinoma (PTMC) based on histological evaluation of the total gland among a group of adults in Brasilia, Brazil, and compare the data with the clinical suspicion of PTMC established by FNA and ultrasonography (USG). PATIENTS AND METHODS: Retrospective cohort study based on medical records of 76 patients who underwent surgical thyroidectomy treatment for several types of thyroid diseases at the University Hospital of Brasilia - Brazil, from 2005 to 2015. A full inclusion of the surgical specimen was made and stained with hematoxylin and eosin. All of the preparations were evaluated by an expert pathologist. The histopathological report was compared to the previous clinical diagnosis, which was based on FNA and USG of the gland. In addition, the exams results were stratified by the Bethesda criteria. RESULTS: Seventy-six individuals with the histopathology diagnosis of PTMC were included (68 were females). A total of 65 FNA and 57 USG results were evaluated, 6 patients had only the histopathologic diagnosis of PTMC. A total of 52 patients had both USG and FNA of the thyroid. All of the patients that had USG records had at least one thyroid nodule, 52,6% of them had multiple nodules. Regarding the FNA results, only 9,2% were classified as Bethesda I; 21,5% as Bethesda II; 7,7% Bethesda III; 7,7% Bethesda IV; 10,8% Bethesda V; 43,1% Bethesda VI. At this cohort, 19 patients were false negatives. The sensibility of FNA for diagnosis of PTMC was 67,79%. CONCLUSION: Despite careful evaluation of the patients, there might have false negatives results. Total thyroid total inclusion of surgical specimen is not a routine diagnostic tool, making less invasive new diagnosis methods desirable.

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<![CDATA[MON-446 Anaplastic Thyroid Cancer Presenting with Brain Metastasis: 17-Year Progression Free Survival]]> https://www.researchpad.co/article/elastic_article_6208 Background: Anaplastic Thyroid Cancer is the most aggressive thyroid cancer with a median survival of just five months. Long term survival has been reported in locally aggressive cases, but has yet to be reported in metastatic disease.

Case Information: A 34-year-old male presented with symptoms of dizziness, confusion, intermittent headaches, and erratic behavior for two weeks. CT of the head revealed a 1 cm ring enhancing lesion in the left parietal lobe with surrounding vasogenic edema. He was taken to the operating room for a left parietal craniotomy and a vascular, solid mass was removed. Initial pathology suggested papillary thyroid origin due to positive staining for thyroid transcription factor (TTF) and thyroglobulin (Tg). On exam, he had a palpable 3 cm mass in the right thyroid lobe with no associated adenopathy. He underwent thyroidectomy to optimize post-operative radioactive iodine treatment. Intraoperative frozen section revealed anaplastic thyroid cancer and final pathology revealed anaplastic carcinoma identical to the brain lesion. The tumor pathology showed extension through the thyroid capsule with lymphovascular invasion and one of two positive lymph nodes. Post-operatively, he underwent 15 cycles of whole brain radiation therapy for a total of 35 Gy. Two additional brain lesions were identified after thyroidectomy and a third was identified after whole brain radiation. He underwent stereotactic radiosurgery of these three lesions less than two months after thyroidectomy. The patient went on to receive modified mantle field irradiation (46 cycles, total 55.2 Gy) to the neck, thyroid bed, and the upper mediastinum. Additionally, he received chemotherapy with doxorubicin 6-8 weeks and temozolomide for 2 years. Thyroid uptake studies showed minimal residual iodine-avid disease and, in the setting of chemotherapy-induced cytopenias, radioactive iodine treatment was not administered. The patient has currently survived 17 years post-treatment. His persistent, but stable, brain lesions are being followed with serial imaging. He remains clinically and neurologically asymptomatic.

Conclusions: This is the first case presenting with long-term survival in a patient with metastatic anaplastic thyroid carcinoma. A multidisciplinary course with early aggressive surgical removal, adjuvant treatment with chemotherapy and radiation, and long term imaging follow up may be an acceptable treatment plan for stable patients.

References:

Smallridge RC, Ain KB, Asa SL, Bible KC, Brierley JD, Burman KD, et al. American Thyroid Association guidelines for management of patients with anaplastic thyroid cancer. Thyroid. 2012;22(11):1104-39.

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<![CDATA[MON-438 Papillary Thyroid Carcinoma Arising in a Thyroglossal Duct Cyst: A Case Report]]> https://www.researchpad.co/article/elastic_article_6075 Introduction: Thyroglossal duct cysts (TGDCs) are uncommon benign congenital entities. Rarely, thyroid carcinoma can arise from a TGDC; the most common being papillary thyroid carcinoma (PTC). Similar to TGDC, carcinomas originating within them can present as an asymptomatic midline neck mass. Signs of malignancy include dysphagia, dysphonia, weight loss, and rapid growth. Given the rarity of TGDC carcinomas, clinical management remains controversial, particularly regarding the requirement for total thyroidectomy.

Case: A 52-year-old female with history of an anterior central neck mass initially noted in 2017. A 0.3-cm left lobe mid-segment cyst and a complex thyroglossal avascular simple cyst measuring 2.4 × 1.1 × 1.8 cm was observed during ultrasound (US). She presented to the endocrinology clinic in April 2019 due to progressive enlargement of the mass.

Repeat thyroid US revealed that the cystic structure had become complex with a peripheral solid component and measured 3.3 × 2.1 × 2.2 cm. FNA was performed and found to be suspicious for PTC (Bethesda category V) and positive for the BRAF V600E mutation.

Patient was referred for surgical evaluation. Physical examination revealed a midline anterior 10-cm, painless, and fixed mass above the thyroid that moved with deglutition and tongue protrusion. Contrast computed tomography scan showed a large multiloculated cystic structure measuring 4.1 × 4.4 × 5.9 cm. A lobulated soft tissue mass measuring 2.2 × 2.4 × 3.0 cm was noted internally along the inferior margin of the cyst. She underwent en-block resection of the TGDC in addition to a total thyroidectomy. Histopathological examination identified a 7.5 × 5.5 × 5.0 cm cystic mass with fluctuation and a firm, solid area in the lower portion measuring 2.6 × 2.4 cm. Thyroid gland examination was otherwise unremarkable. No areas of extension of the mass into the thyroid tissue were clearly identified and no other gross lesions were observed. The solid area within TGDC contained a tumor with findings characteristic of PTC. Postoperatively, she was placed on thyroid hormone replacement therapy.

Conclusion: The main difficulty encountered with cancer developing from TGDC is that the diagnosis is usually made during surgery and from definitive pathological samples. The most common surgical procedure used is the Sistrunk procedure. Some studies have suggested that this procedure alone is an adequate therapy, but others advocate the need for total thyroidectomy. The Sistrunk procedure is considered to be appropriate for low-risk patients, but high-risk patients must undergo total thyroidectomy. The decision to perform a total thyroidectomy in this patient was based on her high-risk classification due to: age, sex, cyst size, and a positive FNA for malignancy. Follow-up includes an annual physical examination, thyroglobulin levels, and an US every 6 months during the first year and annually thereafter.

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<![CDATA[MON-436 Cribriform-morular Variant of Papillary Thyroid Carcinoma: A Case Report]]> https://www.researchpad.co/article/elastic_article_6046 Background:

Cribriform - morular variant is a rare variant of papillary cancer with 1–2 % prevalence. There are no established guidelines to screen for thyroid cancer in patients with APC gene mutations and FAP. We present a case of a young female with APC gene mutation and thyroid cancer.

Case:

Female, 25 years-old, without anemia, underwent colonoscopy at age 22 and multiple polyps were seen. One polyp showed intramucosal carcinoma with high-grade dysplasia. She was diagnosed with FAP. She was found to have APC gene mutation on genetic analysis. No family history of FAP was reported.

Chest and abdominal CT showed multiple thyroid nodules.

Thyroid ultrasound showed 3 nodules. The largest is in the mid R lobe, measuring 1 cm, and is isoechoic to hypoechoic, containing some small central cystic areas. The nodules in the left lobe measure 0.6 and 0.7 cm.

FNA of the right thyroid nodule showed follicular neoplasm. Afirma was suspicious.

She underwent total thyroidectomy.

Pathology report showed multifocal tumor in both right (0.8 cm) and left lobe (0.5 cm). Histologic type was Papillary carcinoma, cribriform - morular variant. All surgical margins were negative. No angio-lymphatic invasion or extra thyroidal extension was identified.

Pathologic stage classification was m pT1a pN0 pM0.

Patient did not receive RAI ablation.

Patient doing well and no further recurrence of thyroid cancer is noted.

Discussion:

Patients with FAP have a greatly increased risk for colorectal cancer and also have an elevated risk for other cancers including thyroid cancer (1%-2% compared to 1% in general population). According to ACG guidelines of 2015, annual thyroid screening by ultrasound should be recommended to individuals affected with FAP. Additionally, thyroid cancer found in unscreened patients with FAP was more advanced as compared to patients screened for cancer requiring less aggressive approaches. On ultrasonography, most nodules had benign-looking features (well-defined, hypoechoic, oval to round shapes without calcification), but some nodules had capsular invasion and larger height: width shape. In preoperative FNA, they were diagnosed as CMV-PTC/PTC but could also present as follicular neoplasm or PTC-follicular variant. Compared to conventional PTC, CMV-PTC had a lower frequency of lymph node metastases at presentation (12%) and distant metastases (3%) as well as lower recurrence rates (8.5%) and patient mortality rates (2%). Physical exam and clinical history is not sufficient to screen for cancer.

In patients with APC gene mutations and FAP, there should be high suspicion for diagnosing thyroid cancer as the nodules are usually benign looking and small in size. As noted in the case, nodules were found incidentally, and tumor size was small with benign looking nodules. Additionally, screening should be focused more on young females below the age of 35 because of the high prevalence of cancer.

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<![CDATA[MON-448 Detection of Thyroid Cancer Recurrence in Patients with Positive Thyroglobulin Antibody Receiving Immunoglobulin Therapy]]> https://www.researchpad.co/article/elastic_article_5956 Introduction: Differentiated thyroid cancers such as papillary and follicular thyroid cancer make up more than 90% of all thyroid cancers. The presence of thyroglobulin autoantibodies makes interpretation of the thyroglobulin level unreliable, as it could be falsely low or falsely high. Studies have shown that rising thyroglobulin antibody levels, could be used to monitor for disease recurrence in patients with negative thyroglobulin and imaging studies. However, there are challenges in detecting recurrence in patients with normal thyroglobulin level and thyroid imaging studies, who are on lifelong immunoglobulin therapy and who have increasing thyroglobulin antibody levels.

Clinical case: A 63 yr old female was found to have an incidental left thyroid nodule at age 48yrs from a carotid ultrasound. She underwent US guided FNA of the thyroid nodule and was found to have papillary thyroid cancer. She had total thyroidectomy a month later, with removal of a 1.4cm primary, with no evidence of extrathyroidal extension, clear margins and no evidence of lymphovascular invasion – Stage T1bN0M0. There was left level 6 neck dissection with no carcinoma identified in the 2 lymph nodes removed. She received 105.3 mCi radioactive iodine (RAI) and whole body thyroid scan done 7 days later revealed, increased uptake involving the thyroid bed likely residual thyroid tissue. Activity was noted inferolateral to the right thyroid bed which most likely represents a lymph node. There was no evidence of distant metastasis.

She was commenced on levothyroxine post operatively. Her other past medical history is significant for idiopathic urticaria and angioedema, immune deficiency disorder with low IgG and IgM and asthma. She was commenced on monthly IV immunoglobulins 5yrs post RAI therapy, due to recurrent sinusitis, rhinitis and chronic diarrhea. She was later transitioned to weekly SQ immune globulin – Hizentra which she is on till date.

Over the past 15 years, serial neck ultrasounds post radioiodine ablation have been negative for recurrence. Her TSH ranged 14.91 to 0.04 (ref 0.27-4.2 uiu/ml) and thyroglobulin (Tg) titer remains <0.1 (ref <0.1). Her thyroglobulin antibody titers have trended up from <0.2 (ref <2.0) 5yrs post RAI therapy to 49 (ref <4 iu/ml)) on her most recent test this year. She is currently undergoing further work up to rule out recurrence of her cancer. In our review of the literature we found one report that showed use of Liquid Chromatography–Mass Spectrometry (LC-MS) was able to differentiate thyroid cancer recurrence in an individual with positive antithyroglobulin antibody receiving immunoglobulin therapy.

Conclusion: In patients with negative Tg levels, but elevated thyroglobulin antibody while receiving immune globulin therapy, thyroglobulin antibody levels may not be a reliable indicator of thyroid cancer recurrence. Measurement of Tg levels using a LC-MS may provide some clarity.

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<![CDATA[MON-454 Lower Extremity Leiomyosarcoma Metastatic to a Benign Thyroid Nodule]]> https://www.researchpad.co/article/Ndb7fbb82-bbd3-4df4-ab5c-97d21fbc9cbd <![CDATA[MON-452 Poorly Differentiated Thyroid Carcinoma Metastatic to the Adrenal Gland]]> https://www.researchpad.co/article/N56db04cd-f26b-4f8b-a4d2-04fb1160183d

Abstract

: Poorly differentiated thyroid carcinoma (PDTC) constitutes 1-15% of all thyroid cancers.

Invasive adrenal metastases secondary to PTDC are exceedingly rare.

: A 64-year-old woman with a non-toxic multinodular goiter presented with right upper quadrant abdominal pain and distension for three months. CT imaging revealed a 13.5 cm right suprarenal retroperitoneal mass invading the liver and inferior vena cava (IVC), concerning for adrenocortical carcinoma. She underwent resection of the mass with

right adrenalectomy, partial hepatectomy, and IVC resection. Pathology demonstrated metastatic thyroid cancer with necrosis of the adrenal gland and IVC. Immunohistochemical staining was positive for PAX8, TTF1, and thyroglobulin (Tg). Completion thyroidectomy revealed an encapsulated 2 cm focus of PDTC with Hurthle cell phenotype in the right thyroid lobe. The mitotic activity was 5/10 per HPF. There were focal areas of tumor necrosis, 3 foci of capsular invasion, and extensive angioinvasion. Surgical margins were free of tumor invasion. Eight resected lymph nodes were negative for malignancy (Stage T1bN0M1; AJCC 8, Stage IVb). Genetic testing was positive for somatic mutations of

,

,

, and

with broad copy number loss on chromosome 22q conferring aggressive tumor behavior.

MRI of the brain and spine ruled out additional metastases. A radioactive iodine (RAI) whole-body scan (WBS) showed residual uptake of 7.6% in the right thyroid bed and a focus of increased uptake at the right sternoclavicular joint. A therapeutic dose of 206 mCi of I-131 was administered. A post-therapy WBS demonstrated focal activity in the right thyroid bed, distal right clavicle, and lower lung lobes. Chest CT and MRI of the right shoulder revealed no structural evidence of metastases corresponding to radiotracer uptake. The stimulated Tg level prior to RAI was 323 ng/mL with a TSH of 66 uU/mL (0.4-4.6 uU/mL). Tg antibodies were undetectable. She was maintained on 150 mcg of levothyroxine with the goal of TSH suppression. Tg levels declined to 4.8 ng/mL at three months, and to 0.3 ng/mL eight months post-RAI.

: PDTC is an aggressive thyroid cancer subtype with distant metastasis reported in 36-85% of cases.

Distant metastasis is predictive of poorer outcomes, with patients three times more likely to die from the disease than those without metastatic disease.

Adrenal metastasis of thyroid cancer is rare, and unlike in our patient, usually asymptomatic and frequently detected on a post-therapy scan. Despite a dramatic response to therapy, given the poorly differentiated features of the primary tumor, a whole-body PET-CT is warranted to evaluate for RAI refractory disease.

References:

1. Ibrahimpasic T et al. J Clin Endocrinol Metab. 2014;99(4):1245-52.

2. Sanders EM Jr et al. World J Surg. 2007;31(5):934-45.

3. Cheng DT et al. J Mol Diagn. 2015;17(3):251-64.

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<![CDATA[MON-451 An Unusual Case of Follicular Thyroid Cancer with Pulmonary Metastasis and Concurrent Hyperthyroidism]]> https://www.researchpad.co/article/Nac3f1bb6-fb40-4983-8707-3a50a61f017a

Abstract

Introduction: Follicular Thyroid Cancer (FTC) accounts for approximately 12 % of all thyroid cancers and is the second most common cause of differentiated thyroid cancer. However, coexisting hyperthyroidism and thyroid malignancy is considered a rare event and is thought to have a prevalence of 0.21–9.0 %. We describe a compelling case of metastatic FTC initially presenting with subclinical hyperthyroidism progressing to overt hyperthyroidism.

Clinical Case: An 88-year-old man with a history of prostate cancer, previous tobacco dependence, and hypertension initially presented with complaints of a chronic non-productive cough associated with unintentional weight loss and fatigue. Initial imaging included a chest CT that showed several bilateral pulmonary nodules suspicious for metastatic disease, as well as an enlarged left-sided thyroid mass, which extended from the inferior pole into the mediastinum. FDG PET/CT showed avid disease identified in the lung. CT-guided lung biopsy was performed, and histopathology revealed FTC. Thyroid function tests (TFTs) revealed a Tg level of 1427 (0.00–33.70), TgAb <1.0 (< 13.6), TSH 0.05 (0.40–4.50), FT4 1.1 (0.8–1.8) and FT3 3.4 (2.3–4.2). Biochemical testing was consistent with subclinical hyperthyroidism. Neck ultrasound showed bilateral thyroid nodules, the largest located on the left mid-pole measuring 3.4 x 3.2 x 3.7 cm. He underwent a whole-body I-131 diagnostic scan, which showed intense uptake of the radionuclide within the thyroid gland, more evident on the left, but additional metastatic lesions elsewhere in the visualized body were not possible. TFTs were repeated, which showed a TSH of 0.01, FT4 of 2.0, and FT3 of 6.4. He was subsequently started on methimazole daily and eventually became euthyroid. Due to advanced age, significant mediastinal extension, and lung metastasis, the patient was not a candidate for surgical resection and treatment with a targeted tyrosine kinase inhibitor. He ultimately opted for an observational approach.

Conclusion: Although metastatic FTC carries a poor prognosis, concurrent hyperthyroidism is thought to be associated with a more aggressive disease course and higher mortality compared to differentiated thyroid cancers in euthyroid patients.

Sources: 1. Pazaitou-Panayiotou, K., Perros, P., Boudina, M., Siardos, G., Drimonitis, A., Patakiouta, F., & Vainas, I. (2008). Mortality from thyroid cancer in patients with hyperthyroidism: the Theagenion Cancer Hospital experience, European Journal of Endocrinology, 159(6), 799–803.

2. Benjamin Momo Kadia, Christian Akem Dimala, Ndemazie Nkafu Bechem, Desmond Aroke. BMC Res Notes. 2016; 9: 369.

3. Parameswaran R, Shulin Hu J, Min En N, Tan WB, Yuan NK. Patterns of metastasis in follicular thyroid carcinoma and the difference between early and delayed presentation. Ann R Coll Surg Engl. 2017;99(2):151–154.

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<![CDATA[MON-439 Graves’ Disease and Papillary Thyroid Cancer: A Rare Clinical Case?]]> https://www.researchpad.co/article/N83803509-5647-4474-9d42-8e106852ea61 <![CDATA[MON-442 Tall Cell Variant of Papillary Thyroid Carcinoma Presenting Acutely as a Right Thyroid Mass and Thyroiditis - an Unusual Presentation]]> https://www.researchpad.co/article/N2773b0ed-324e-49f5-9a5b-8695c183b7ec <![CDATA[MON-455 Papillary Thyroid Carcinoma in the Thyroglossal Duct]]> https://www.researchpad.co/article/Nb9b907d8-dbe5-43da-95f8-f9abda7cc11c <![CDATA[MON-447 Schwannoma Masquerading as Metastatic Papillary Thyroid Carcinoma in a Cervical Lymph Node]]> https://www.researchpad.co/article/N7a9e33e6-d80d-4100-ab36-c06947e2ae23 <![CDATA[MON-457 Reactive Thyroid C-Cell Hyperplasia or Medullary Thyroid Cancer in a Patient with Nodular Thyroidopathy. May the Calcitonin Measurement in Fine-Needle Aspirate Washout Fluid of the Healthy Lobe Help to Define These Conditions?]]> https://www.researchpad.co/article/Ndf972a91-d5c7-432f-b90a-e9423c27e50c 2000 pg/ml) were determined in follow-up group. The remaining 3 patients with nodules (Bethesda IV-VI) and FNA-CT of healthy lobe which did not exceed bCT rate, were operated. MTC was confirmed. Discussion: Our patient had not only many factors which can occur his bCT level (obesity, smoking), but also unfavourable FNA washout results. Additionally, since in clinical studies GLP-1 receptor activation has been associated with C-cell hyperplasia (CCH), we cannot completely exclude the possible effect of this treatment on patient’s bCT level. We confronted a situation when, on the one hand, FNA-CT data indicate the MTC nature of hypercalcitoninemia, but on the other hand, decreasing bCT-level in dynamic observation is not common for MTC. FNAB of the healthy lobe and obtaining high rates of CT in the washout fluid sample allowed us to confirm the diffuse CCH process, thus to follow up these patients. CT stimulation test cannot distinguish between minimal MTC and CCH and has no reference range. The weak point of the proposed study is the lack of morphological data in the follow-up group of patients. Conclusion: It is possible to use rate of FNA-CT of the healthy lobe to differentiate between various C-cell diseases, but requires new data. ]]>