Papillary thyroid carcinoma frequently metastasizes to regional lymph nodes. However, cervical lymph node metastasis as a sole manifestation of occult papillary thyroid carcinoma is rarely observed. Ectopic thyroid is an uncommon condition defined as the presence of thyroid tissue at a site other than pretracheal area. Approximately 1–3% of all ectopic thyroid tissue is located in the lateral neck. This entity may represent the only functional thyroid tissue in the body. Malignant transformation of ectopic thyroid is uncommon; but even rarer is the development of papillary carcinoma on it. We present a case of a 33-year-old man with an incidental lateral neck mass diagnosed after a motor vehicle accident. Total thyroidectomy and lymph node resection were completed without evidence of papillary thyroid carcinoma. Malignant transformation of heterotopic thyroid tissue was the final diagnosis. The possibility of an ectopic thyroid cancer should be considered in the differential diagnosis of a pathological mass in the neck. The uniqueness of this case strives in the rarity that the thyroid gland was free of malignancy, despite ectopic tissue being positive for thyroid carcinoma. Management strategies, including performance of total thyroidectomy, neck dissection, and treatment with radioiodine, should be based on individualized risk assessment.

Differentiated thyroid cancer arises from thyroid follicular epithelial cells. It accounts for more than 90% of thyroid cancers. In areas of sufficient iodine nutrition, about 85% of differentiated thyroid cancers are papillary, 10% are follicular and 3% are Hurthle cell carcinomas. The coexistence of different types of thyroid cancer in a single patient is a rare condition. This is the case of a 56 year-old man with medical history of arterial hypertension who presented to clinics with right shoulder pain. Imaging of the right shoulder showed a osteolytic lesion involving the right humerus with associated cortical disruption consistent with pathological fracture secondary to metastatic disease. Bone biopsy showed papillary thyroid carcinoma. Subsequently, ultrasound-guided fine needle aspiration biopsy to a right lobe nodule was performed, which confirmed the presence of papillary thyroid carcinoma. There was also evidence of cervical lymph node involvement. Patient proceeded to total thyroidectomy with neck dissection, and surgical pathology revealed the presence of 2.5 cm right lobe papillary carcinoma and 1.5 cm left lobe follicular carcinoma. Postoperatively, he was found with persistent elevated thyroid-stimulating hormone (TSH) and elevated quantitative thyroglobulin with elevated thyroglobulin antibodies. Patient received therapeutic radioiodine (I-131) for ablation of thyroid cancer. Whole body iodine scan demonstrated residual functioning thyroid tissue within post-thyroidectomy bed, with or without residual carcinoma, and large expansile uptake lesion involving the right humeral head and neck. Therefore, patient will receive a second dose of radioactive iodine. He has been started on thyroid hormone replacement with a goal of TSH <0.1 uIU/mL for high risk American Thyroid Association (ATA) stratification, and has remained clinically euthyroid. Thyroid carcinoma is the most common endocrine malignancy and one of the most rapidly increasing cancers in the United States. This increase in incidence is largely due to incidental detection on diagnostic imaging. Here we present an uncommon case of two distinct thyroid malignancies occurring simultaneously in a patient presenting with a pathological fracture. Synchronous occurrence of two types of differentiated thyroid cancer is a rare event, and has only been reported in case series. Bone metastasis from differentiated thyroid cancer can occur in 2-13% of patients. Despite the therapy for papillary thyroid carcinoma and follicular thyroid carcinoma remain the same, proper identification will lead to prompt therapy and increased survival. Physicians should be aware of this variety.

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Cluster of differentiation 52 (CD-52) is a glycoprotein expressed on the surface of most lymphocytes and it is the most prevalent marker in T cells, B cells, natural killers and monocytes. Alemtuzumab, a CD-52 monoclonal antibody, is one of the initial therapies approved for patients with relapsing-remitting multiple sclerosis. It acts by inducing rapid and prolonged depletion of lymphocytes with a consequent immunosuppression. Although not clearly understood, Alemtuzumab has been associated with the development of autoantibodies. These have been reported to cause thyroid injury resulting in 10-15% incidence of new-onset Graves’ disease. This is the case of a 38 year-old man with medical history of relapsing-remitting multiple sclerosis who came to the Endocrinology clinic to establish care due to abnormal thyroid function tests. Patient has received Alemtuzumab since the past two years. Three months prior to arrival, he was found with weight loss, hyperdefecation and tremors by his Neurologist. Patient was found with suppressed TSH for which Methimazole was commenced. Thyroid ultrasound showed normal size and homogenous right and left thyroid lobes, and no evidence of cystic or solid masses. Thyroid stimulating immunoglobulins were found elevated which correlated with Graves’ disease. Moreover, thyroid scintigraphy showed 34% radioiodine uptake at 24 hours indicating de novo synthesis of thyroid hormone in this patient with hyperthyroidism. As Alemtuzumab was identified as a precipitating cause of Graves’ disease, therapy was discontinued and plasmapheresis will be given for the treatment of relapsing-remitting multiple sclerosis. Monoclonal antibody use has increased since the past decades. It has been well described in literature that monoclonal antibodies against programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) may cause autoimmune thyroid disease. Nonetheless, it is important to recognize that other monoclonal antibodies may have similar adverse effects. Alemtuzumab is a monoclonal antibody and antineoplastic agent used for relapsing multiple sclerosis, some hematologic malignancies, and as an induction agent for solid organ transplantation. Its main effects include autoimmunity with thyroid being one of the most described targets. In these patients, expert clinicians should recognize the possibility of thyroid disease for prompt treatment which will improve quality of life.