Mitochondrial DNA copy number and risk of papillary thyroid carcinoma.

BACKGROUND: Mitochondrial DNA (mtDNA) copy number is associated with tumor activity and carcinogenesis. This study was undertaken to investigate mtDNA copy number in papillary thyroid cancer (PTC) tissues and to evaluate the risk of PTC development. The clinicopathological features of patients and mtDNA copy number were correlated. The value of mtDNA copy number was evaluated as a biomarker for PTC. METHOD: DNA was extracted from 105 PTC tissues and 67 control thyroid tissues, and mtDNA copy number mtDNA oxidative damage were determined using qPCR techniques. RESULTS: Overall, the relative mtDNA copy number was significantly higher in PTC patients (p < 0.001). The risk of developing PTC increased significantly across the tertiles of mtDNA copy number (p trend < 0.001). The higher the mtDNA copy number tertile, the greater the risk of developing PTC. Patients with follicular variants had an odds ratio of 2.09 (95% CI: 1.78-2.44) compared to those with classical variants (p < 0.001). The level of mtDNA oxidative damage in PTC was significantly elevated compared to controls (p < 0.001). The ROC analysis of mtDNA copy number indicated an area under the curve (AUC) of 77.7% (95% CI: 0.71 to 0.85, p < 0.001) for the ability of mtDNA copy number z-scores in differentiate between PTC and controls. CONCLUSION: Our results indicated that the augmentation of mtDNA content plays a significant role during the initiation of thyroid cancer, and it might represent a potential biomarker for predicting the risk of PTC.

Pulmonary Metastatic Follicular Thyroid Carcinoma Without Intrathyroidal Primary Thyroid Cancer.

Background/Objective: Follicular thyroid cancer without an intrathyroidal primary cancer is rare. We present a patient with multifocal pulmonary metastatic follicular thyroid cancer without apparent cancer within her thyroid. Case Report: A 44-year-old woman was referred to the thyroid cancer clinic via telemedicine for evaluation of intrapulmonary thyroid tissue. Her past medical history included Roux-en-Y gastric bypass and hysterectomy with bilateral oophorectomy. Six months prior, abdominal computed tomography (CT) showed incidental bilateral lung nodules. Chest CT demonstrated 4 solid left and 1 solid right lung nodules. Lung nodule core biopsy revealed benign thyroid tissue. Thyroid ultrasound showed bilateral subcentimeter anechoic nodules. Chest CT 6 months after initial CT demonstrated stable lung nodules. The levels of thyroid-stimulating hormone, serum thyroglobulin, and thyroglobulin antibody were 1.63 mIU/L (reference range, 0.3-5.5 mIU/L), 40.9 ng/mL (reference range, 0-35 ng/mL), and <1 IU/mL (reference range, <4), respectively. Positron emission tomography/CT showed fluorodeoxyglucose-avid lung lesions measuring 1.5, 1.1, and 2.2 cm and other subcentimeter pulmonary nodules. Repeat lung core biopsy showed thyroid tissue with microfollicular architecture, favoring metastatic follicular carcinoma with neuroblastoma-RAS gene (NRAS) mutation. Total thyroidectomy performed showed multinodular hyperplasia without thyroid cancer. Her postoperative radioiodine scan demonstrated bilateral iodine-avid pulmonary nodules, a serum thyroglobulin level of 179.8 ng/mL, a thyroid-stimulating hormone level of 151.3 mIU/L, and undetectable serum thyroglobulin antibody. She received 261 mCi of radioactive iodine. Fourteen months later, chest CT revealed decreased lung nodules and a serum thyroglobulin level of 0.7 ng/mL. Discussion: Approximately 2 cases of multifocal pulmonary follicular thyroid cancer without a primary source and no other site of metastasis have been reported. Conclusion: Pulmonary follicular thyroid cancer without a primary source and no other site of metastasis is extremely rare.

Case report: - A case report on the management of symptomatic Lingual throid.

INTRODUCTION: The lingual thyroid gland refers to ectopic thyroid tissue situated at the base of the tongue. This rare condition occurs when the thyroid gland fails to descend to its usual position in the pre-tracheal area during embryonic development. CASE PRESENTATION: We present a case of a 23-year-old female who presented with throat discomfort and progressive difficulty of swallowing upon examination there was a mass at the level of the base of the tongue. She was investigated with a thyroid function test, neck ultrasound, at the tongue's base, and head and neck CT scan. With a diagnosed lingual thyroid she was managed initially with suppression therapy followed by elective surgical removal. The work has been reported in line with the SCARE criteria. CLINICAL DISCUSSION: The incidence of lingual thyroid is reported to be 1 in 100,000, with a higher prevalence among females, in a ratio of 3:1 compared to males. Symptoms can vary and may include difficulty swallowing (dysphagia), voice changes (dysphonia), upper airway obstruction, or occasional bleeding, and can manifest from infancy to adulthood. CONCLUSION: Lingual thyroid is a rare clinical anomaly treatment depending on the severity of symptoms, size of the lesion, sex and age of the patient, and thyroid function.

Ectopic Thyroid Tissue in the Anterior Mediastinum: A Case Report.

Ectopic thyroid tissue (ETT) is a rare finding on mediastinoscopy which could be attributed to a defect early in thyroid gland embryogenesis, as the glandular tissue makes its way to a pre-tracheal position. The more distal the location of the ectopic tissue from typically neighboring structures, such as the recurrent laryngeal nerves or the superior thyroid artery, the greater the likelihood for issues such as hyperthyroidism, compression of nearby neurovascular structures, and malignancy. Depending on the exact anatomical location and hormonal activity of the tissue, management can range from administration of iodine to surgical resection. This report discusses a case of ETT discovered during the resection of an anterior mediastinal mass, possible treatment, and management plans.

Coexistence of Eutopic Thyroid Gland and Ectopic Thyroid Tissue: Rare but Not Uncommon.

Ectopic thyroid tissue is very rare, but the coexistence of ectopic and eutopic thyroid glands is even more rare. The recognition of this diagnosis is important in patients who are being treated for thyrotoxicosis, but it is also crucial to exclude other associated serious disease conditions. In this article, we report three different cases that showed ectopic thyroid tissue with the coexisting presence of an eutopic thyroid gland. All three cases showed different outcomes. The recognition of this condition is of great importance because it alerts the referring physicians to this rare, yet possible occurrence and the potential pathological conditions associated with it. The first case showed how imaging could help outline even small ectopic thyroid tissue outside of the neck region even in cases where histopathological confirmation is difficult. The second case was very rare as thyroid carcinoma originated in ectopic thyroid tissue. In the last case, the initial imaging was misleading as it mimicked greatly ectopic thyroid tissue, and only detailed history and careful inspection of the images could lead to the correct interpretation of the findings.

Primary Intrathoracic Ectopic Papillary Thyroid Carcinoma, Presenting With Thoracic Spine Metastasis: A Case Presentation and Literature Review.

Thyroid cancer in ectopic thyroid tissue is a very rare entity. We report a patient with papillary thyroid cancer arising from upper mediastinal ectopic thyroid tissue. The patient presented with thoracic spine metastasis with cord compression. The patient was a 67-year-old woman, who presented with upper back pain. Magnetic resonance imaging (MRI) showed suspected metastatic disease in the second and third thoracic vertebrae (T2 and T3). She underwent laminectomy and decompression surgery at the T1-T3 level. The final pathology report showed metastatic thyroid carcinoma with papillary features. She underwent external beam radiation to the affected spine. Computerized tomography (CT) scan of the chest, abdomen, and pelvis showed a 3.0 × 2.8 × 2.3 cm soft-tissue mass in the left superior mediastinum extending into the supraclavicular region. Fluorodeoxyglucose-positron emission tomography (FDG-PET) scan showed hypermetabolic foci in the upper mediastinum. Fine needle aspiration (FNA) of the upper mediastinal mass was consistent with papillary thyroid cancer. Molecular testing from the FNA sample using Thyroseq V3 showed SQSTM1NTRK3 chromosomal rearrangement. A total thyroidectomy was performed. Pathology of the resected thyroid was benign. Pathology of the mediastinal mass showed a papillary thyroid carcinoma with focal tall cell features, forming a 4 × 2.5 × 2.5 cm mass. Surgery was followed by ablation with 100 millicuries (mci) of radioactive iodine (I-131) and external beam radiation. This case highlights the presentation of primary intrathoracic papillary thyroid cancer with SQSTM1-NTRK3 chromosomal rearrangement and the challenges in the diagnosis and management of this unique case. This patient had a very aggressive disease presentation that required multimodal treatment, including thoracic spine decompression, total thyroidectomy, primary intrathoracic goiter resection, high-dose radioactive iodine treatment, and external beam radiation to the affected spine area. SQSTM1-NTRK3 chromosomal rearrangement can be targeted by medications such as larotrectinib and endtrectinib.

Domain transformation using semi-supervised CycleGAN for improving performance of classifying thyroid tissue images.

PURPOSE: A large number of research has been conducted on the classification of medical images using deep learning. The thyroid tissue images can be also classified by cancer types. Deep learning requires a large amount of data, but every medical institution cannot collect sufficient number of data for deep learning. In that case, we can consider a case where a classifier trained at a certain medical institution that has a sufficient number of data is reused at other institutions. However, when using data from multiple institutions, it is necessary to unify the feature distribution because the feature of the data differs due to differences in data acquisition conditions. METHODS: To unify the feature distribution, the data from Institution T are transformed to have the closer distribution to that from Institution S by applying a domain transformation using semi-supervised CycleGAN. The proposed method enhances CycleGAN considering the feature distribution of classes for making appropriate domain transformation for classification. In addition, to address the problem of imbalanced data with different numbers of data for each cancer type, several methods dealing with imbalanced data are applied to semi-supervised CycleGAN. RESULTS: The experimental results showed that the classification performance was enhanced when the dataset from Institution S was used as training data and the testing dataset from Institution T was classified after applying domain transformation. In addition, focal loss contributed to improving the mean F1 score the best as a method that addresses the class imbalance. CONCLUSION: The proposed method achieved the domain transformation of thyroid tissue images between two domains, where it retained the important features related to the classes across domains and showed the best F1 score with significant differences compared with other methods. In addition, the proposed method was further enhanced by addressing the class imbalance of the dataset.

Rare Coexistence of Aldosterone-producing Adrenocortical Adenoma Confirmed by an Immunohistochemical Analysis of Steroidogenic Enzymes with Adrenal Ectopic Thyroid Tissue: A Case Report and Literature Review.

A 56-year-old man presented with a history of hypertension; clinically, the patient had primary aldosteronism (PA) and a 4-cm left adrenal tumor. The left adrenal glands, resected by adrenalectomy, also contained ectopic thyroid tissue (ETT). An immunohistochemical analysis of steroid-converting enzymes revealed an aldosterone-producing adenoma (APA). Among 19 previously reported cases of adrenal ETT, 4 had adrenal hormonal abnormalities, all of which were PA. This is the first case of adrenal ETT coexisting with APA, confirmed by steroid-converting enzyme expression. Further analyses using cumulative case data are required to clarify the correlation between adrenal ETT and APA.

Clinical value of Cyclin D1 and P21 in the differential diagnosis of papillary thyroid carcinoma.

BACKGROUND: With the continuous discovery of new borderline thyroid lesions and benign and malignant "gray areas", coupled with the limitations of traditional immune indicators, the differential diagnosis of papillary thyroid carcinoma (PTC) has become more difficult. Cyclin D1 and P21 are cell cycle regulators involved in the occurrence and metastasis of multiple tumors, including PTC, but their specific functions are unclear. METHODS: In our study, immunohistochemical staining was used to explore the expression of Cyclin D1 and P21 in PTC, paracancerous tissue, follicular adenoma (FA) and papillary thyroid hyperplasia. In addition, their relationship with the clinicopathological features of PTC and their differential diagnostic value in distinguishing between intralymph node PTC metastases and intralymph node ectopic thyroid tissue were studied. RESULTS: Among 200 primary PTC lesions, Cyclin D1 and P21 were found to be expressed in 186 (93.00%) and 177 (88.50%), respectively, and their expression levels were significantly higher in PTC tissue than in adjacent tissue, FA tissue and papillary thyroid hyperplasia tissue (P < 0.05). The expression levels of Cyclin D1 and P21 were positively correlated with tumor size and lymph node metastasis (P < 0.05) but not with sex, age, number of tumor lesions, histological subtype, chronic lymphocytic thyroiditis or TNM stage (P < 0.05). The expression levels of Cyclin D1 and P21 were significantly correlated (P < 0.05). The positivity rates of Cyclin D1 and P21 in intralymph node PTC metastases were 97.96% (48/49) and 89.80% (44/49), respectively, which were significantly higher than those in intralymph node ectopic thyroid tissue (P < 0.05). The sensitivity (Se) and negative predictive value (NPV) of Cyclin D1 and P21 detection alone or in combination were higher than those of the combined detection of the classical antibody markers CK19, HBME-1 and Galectin-3. Besides, the Se, Sp, PPV and NPV of Cyclin D1 and P21 in differentiating intralymph node PTC metastases and intralymph node ectopic thyroid tissue were higher. CONCLUSIONS: The results of our study show that Cyclin D1 and P21 are highly sensitive and specific markers for the diagnosis of PTC that are superior to traditional classical antibodies. And, these two markers are of great value in the differential diagnosis of intralymph node PTC metastases and intralymph node ectopic thyroid tissue.

Neoplasms in Struma Ovarii: A Review.

Struma ovarii is a well-known ovarian teratoma made up of benign thyroid tissue. These lesions demonstrate variable, normal architecture and normal thyroid immunohistochemical staining with positivity for TTF1, PAX8, and thyroglobulin. Though most are benign, some of these lesions can also present with a malignant component. Within this article, we review the most common diagnostic malignancies including papillary thyroid carcinoma, strumal carcinoid, highly differentiated follicular thyroid carcinoma, and other thyroid carcinomas. We additionally review the use of TTF1 staining to assist in differentiating these lesions from surrounding gynecologic epithelium, which is imperative in making such diagnoses. In highlighting these entities, we hope to provide practicing pathologists with an effective and concise review of these lesions to assist in more challenging cases of struma ovarii.

Subcutaneous implantation of thyroid carcinoma and benign tissue after thyroidectomy: report on two cases and review of the current literature.

Background: Subcutaneous implantation of thyroid tissue after thyroidectomy is a rare occurrence involving both benign and malignant thyroid tissue. Clinically, subcutaneous implantation of thyroid tissue can be challenging to diagnose. We present two cases of subcutaneous implantation of thyroid tissue following thyroidectomy and discuss the differential diagnosis, clinicopathological characteristics, and the possible mechanism of implantation. Case Description: A 35-year-old woman (age in 2009) who underwent total thyroidectomy in 2009 whose histopathological examination revealed a nodular hyperplasia and lymphocytic thyroiditis complained of palpable mass in her neck 10 years after operation and underwent excision. Follicular adenoma was confirmed in histopathological results. A 58-year-old woman (age in 2010) who underwent lobectomy in 2010 for nodular hyperplasia had a 6 cm sized huge mass in her anterior neck 9 years after operation. Anterior neck mass excision was done and poorly differentiated carcinoma was confirmed in histopathological results. The patient showed no sign of recurrence after 3 years follow-up. Conclusions: Subcutaneous implantation of benign thyroid tissue or thyroid cancer can occur after thyroidectomy. Minimizing the likelihood of subcutaneous implantation requires careful consideration of various factors at every stage of the surgical procedure. Surgeons should be aware of this potential long-term complication that can occur in both conventional thyroidectomy and remote access surgery, effectively communicate and provide appropriate guidance to their patients, and try to avoid seeding of both malignant and benign thyroid tissue.

En bloc resection of pararectal ectopic thyroid tissue: a case report.

A pararectal mass' specific diagnosis can be challenging as a broad range of both benign and malignant tumors are possible. Many of these lesions are congenital and do not require treatment, if asymptomatic. Special attention is to be paid when imaging findings are not typical. In such cases, definitive diagnostic can require surgical excision. To this day, ectopic thyroid tissue was not part of known differential diagnosis. This is the first reported case of thyroid adenoma found in the perirectal area. Ectopic thyroid gland can progress over time and include malignant transformation, although rare. It needs to be considered when managing these cases, especially in unusual locations. This case report offers a systematic approach to the atypical pararectal tumor. It shares new specific clinical experience in managing a case  of pararectal ectopic thyroid adenoma, from both a surgical and a histopathological point of view.

Ectopic thyroid tissue in the breast: A case report.

Ectopic thyroid tissue is a rare condition manifested as the appearance of thyroid tissue outside the thyroid gland. Here, we report a case of ectopic thyroid tissue in the breast. A 48-year-old Chinese woman who was diagnosed with breast cancer received modified radical mastectomy. A thyroid tissue was found on subsequent pathological examination. The ectopic thyroid tissue was confirmed by immunohistochemistry staining of thyroid biomarkers, including thyroglobulin, thyroid transcription factor-1, and thyroid peroxidase. Currently, abnormal thyroid anlage descent is the main theory to explain ectopic thyroid tissue, especially lingual thyroid. However, it is far-fetched to explain the pathogenesis of ectopic thyroid tissues existed in organs or tissues far from thyroid such as iris, cardiac, pulmonary, duodenal, adrenal, and vertebral. Here, we reviewed the previous cases of ectopic thyroid tissue in breast and proposed a "entoderm migration" theory to explain distant ectopic thyroid tissues based on embryonic development perspective.

Tongue Base Ectopic Thyroid Tissue-Is It a Rare Encounter?

Failure in the embryological development of the thyroid in adults is rarely seen. We present the case of a 79-year-old female patient who complained of dysphagia and progressive upper respiratory obstruction, which started 12 months prior to her admission. An ENT clinical exam revealed a tongue base, spherical, well-defined tumour covered by normal mucosa. Further assessments established the diagnosis of the tongue base ectopic thyroid tissue. Due to the patient's symptoms, a transhyoid tongue base tumour removal was performed. The selected patient gave consent for participation and inclusion in this paper, in compliance with the 1964 Helsinki declaration.

Initial results of the INSPIRE clinical trial-investigating radiation dosimetry for differentiated thyroid cancer patients.

Introduction: The optimal strategy for differentiated thyroid cancer (DTC) patients treated with radioiodine (RAI) following thyroidectomy remains controversial. Multi-centre clinical studies are essential to identify strategies to improve patient outcomes while minimising treatment-induced toxicity. Materials and Methods: The INSPIRE clinical trial (ClinicalTrials.gov Identifier: NCT04391244) aims to investigate patient-specific dosimetry for DTC patients and to determine the range of absorbed doses delivered to target and non-target tissues and their relationship with treatment outcome and toxicity. Results: We report here initial results of the first 30 patients enrolled onto the INSPIRE trial. A large range of absorbed doses are observed for both thyroid remnants and salivary glands, with median values of 4.8 Gy (Range 0.2 - 242 Gy) and 0.3 Gy (Range 0.1 to 1.7 Gy), respectively. Discussion: The preliminary study results are encouraging and could help to improve our understanding of absorbed doses to thyroid remnants and normal organs following RAI therapy. Such knowledge could potentially enable patient-specific treatment planning with improved clinical outcomes and quality-of-life of patients.

Case report: surgical management of symptomatic pretracheal thyroid gland in a patient with dual ectopic thyroid.

BACKGROUND: Dual ectopic thyroid, a very rare condition, is defined as the simultaneous presence of ectopic thyroid tissue in two abnormal locations. Here, we report the surgical management of a patient with dual ectopic thyroid. CASE PRESENTATION: The patient was a 12-year-old boy with right para-midline swelling for 2 months. On physical examination of the upper anterior neck, there was a 4 cm × 3 cm mass that was soft, mobile, smooth, and painless. Blood examination showed euthyroidism. Neck ultrasonography showed a well-circumscribed multilocular cyst. We followed up by observation only because the patient had no local symptoms or malignancy. After 2 years, the mass gradually enlarged, so we performed surgery to improve cosmetic outcomes. Preoperative neck CT revealed both a high-density solid mass at the base of the tongue and a central low-density region surrounded by a high-density area at the pretracheal region below the hyoid. The infrahyoid mass was surgically removed, and the sublingual mass was left intact. Pathological findings showed the growth of multiple-size follicles, leading to a diagnosis of adenomatous goiter. Postoperative 123-I scintigraphy showed radioactive iodine uptake in the sublingual lesion, but none in the normal thyroid bed despite the extirpation of thyroid tissue. Postoperative thyroid hormone replacement was started for subclinical hypothyroidism. One year postoperatively, the patient became euthyroid. CONCLUSION: Surgical excision was used to manage a symptomatic cervical infrahyoid mass related to dual ectopic thyroid. Postoperatively, thyroid hormone replacement was required both to prevent enlargement of the remaining sublingual thyroid and to maintain adequate thyroid hormone levels.

Case report: Ectopic thyroid tissue found in a liver with hepatocellular carcinoma.

Background: Concomitant intrahepatic ectopic thyroid is rare in patients with hepatocellular carcinoma. Thyroid follicular structures outside the hepatocellular carcinoma lesions are regarded as satellite nodules or intrahepatic metastases of hepatocellular carcinoma, which often leads to misdiagnosis and overtreatment of hepatocellular carcinoma patients. Case presentation: We report the case of an 83-year-old man with moderately differentiated hepatocellular carcinoma (2.5 cm) whose liver contained ectopic thyroid tissue. An encapsulated, multinodular grayish-yellow mass and multiple satellite nodules were detected and removed by right hepatic lobectomy. Microscopically, the main tumor displayed a predominant trabecular, cord-like structure. Liver tissue 0.5 cm from the tumor had a benign-appearing follicular thyroid structure. The follicles contained colloid tissue and were lined with low cuboidal cells with scant cytoplasm; lymphatic tissue was also present in the area. The hepatocellular carcinoma cells were positive for hepatocyte antigen and glypican-3 and negative for cytokeratin 19. The follicular thyroid cells expressed thyroglobulin, PAX8, and thyroid transcription factor-1. A metastatic thyroid neoplasm was excluded clinically and by ultrasound and computed tomography. One month after surgery, all of the patient's serological markers were normal; no tumor recurrence or metastasis has been detected for 7 postoperative months. Conclusions: The finding of ectopic thyroid tissue in the liver of a patient with hepatocellular carcinoma is very rare. The possibility of hepatocellular carcinoma forming satellite nodules and intrahepatic metastasis should be ruled out first and immunohistochemistry may be definitive in making the diagnosis. Further examination is needed to exclude thyroid cancer liver metastases.

A Unique Presentation of Ectopic Thyroid Tissue: Case Report and Management Principles.

Ectopic thyroid is a rare clinical presentation to encounter in day-to-day clinical practice. It occurs due to developmental defects in the early stages of the thyroid gland embryogenesis during its descent from the floor of the primitive foregut to its final pre-tracheal position. It is usually present along the extent of the thyroglossal duct as well as in distant locations such as sub-diaphragmatic or mediastinal spaces. The diverse clinical presentation of this rare entity often causes a diagnostic dilemma. A thyroid scintigraphy scan is pivotal in the diagnosis of ectopy, but ultrasonography is done more frequently. Surgical management is preferred for symptomatic cases, followed by radioactive iodine ablation and levothyroxine supportive therapy for refractory cases. We present a case of a 62-year-old female patient who presented with pain and swelling of the right submandibular region. On ultrasonography, a 5*4 cm firm mobile swelling of the right submandibular region was found, suggestive of right submandibular sialadenitis. Fine needle aspiration cytology (FNAC) was subsequently done, and it showed features of basaloid neoplasm like pleomorphic adenoma, and as the thyroid tissue was in an ectopic location, it must have been misdiagnosed. The patient was then taken up for right submandibular sialoadenectomy, and the histopathological examination of the operative specimen showed nodular colloidal goiter and mild chronic sialadenitis. Ectopic thyroid can present at various anatomical locations and thereby has varied clinical presentations which makes it a diagnostic dilemma for clinicians. The usual radiological investigations done include USG and CT scan, whereas thyroid scintigraphy is more precise in reaching the diagnosis of ectopic thyroid. The confirmatory diagnostic method is the histopathological examination of the excised specimen. Most cases of ectopic thyroid are asymptomatic and require regular follow-up. Symptomatic cases are managed by surgical excision followed by periodic monitoring and adequate thyroxine replacement.

Thyroid tissue in cervical lymph nodes, not always malignant.

Thyroid tissue in cervical lymph nodes is an interesting and rare phenomenon that cannot be directly explained by embryology. Distinguishing malignant from benign thyroid tissue in cervical lymph nodes can be challenging but is essential for treatment and might have legal implications. Patients with incidentally found thyroid tissue in cervical lymph nodes during thyroid surgery were retrospectively identified. Clinical data and findings on pathology were retrospectively collected. Two patients with thyroid tissue in cervical lymph nodes were identified. Conventional pathology complemented with immunohistochemistry and molecular diagnostics showed the thyroid tissue in cervical lymph nodes to be benign. We show that benign thyroid tissue in cervical lymph nodes can be found in the absence or presence of a primary thyroid malignancy. A conservative approach is recommended if pathology shows benign thyroid tissue in cervical lymph nodes.