Metastatic Papillary Thyroid Carcinoma Gone Wild

Thyroid cancers account for only 1.5% of all cancers in adults and 3% of all cancers in children. In females, however, thyroid cancers are the fifth most common cancer, comprising 4% of all cases. Of all thyroid cancers, 74-80% of cases are papillary cancer. The prevalence of thyroid cancer is rising worldwide. Although thyroid cancer has a favorable prognosis, up to 20% of patients experienced recurrent disease during the follow-up period. Extra-thyroidal extension occurs in 8% to 32% of cases. Local or regional recurrences occur in 5-15% of patients with papillary thyroid carcinoma (PTC). Distant metastasis occurs in only 1% to 25% mostly in the lungs and bones. Our patient is a 68-year-old woman with a past medical history of hypertension and endometriosis. She has metastatic PTC with recurrent metastasis. She had a subtotal thyroidectomy in 2004; radioactive iodine ablation of residual cancer with two recurrent metastases at the right lateral supraclavicular mass and skull base; underwent multiple neck surgeries and resection of skull base lesion in 2014; and local neck resection of right lateral supraclavicular neck mass in 2017. She presented this time with a 6-month history of right submaxillary and right infra-auricular growth. The patient underwent an ultrasound-guided biopsy of tonsillar and submaxillary masses with pathology consistent with PTC. In 2020, the patient was found to have parotid gland involvement. Biopsy of the parotid gland confirmed PTC cells. Recently in 2021 whole-body positron emission tomography/computed tomography (PET/CT) showed early bone metastasis. This case report exem-plifies a highly aggressive PTC with recurrent metastases to sites that have rarely been reported in the past. It also draws our attention to the unknown prognosis of such aggressive metastatic PTC. The presence of metastatic lesions at uncommon sites such as the tonsils, vocal cord, parotid gland, oropharynx and bone metastasis should direct our focus toward a need for further research on metastatic PTC to establish improved management strategies.