Concurrent Hyperthyroidism and Papillary Thyroid Cancer

Background: Concurrent thyroid cancer and hyperthyroidism is rare, though increasingly reported. Hyperthyroidism due to thyroid cancer is very rare and challenging. Case presentation: We present a 35-year-old woman who had been on irregular regimen of propanolol and digoxin as treatment for worsening palpitations for 12 months. She came to our Policlinic University for her propanolol medication evaluation. We identified features of hyperthyroidism and found a left uninodular goiter with no cervical lymphadenopathy. She was referred for thyroid assessment which suggested primary hyperthyroidism and an enlarged heterogeneous left lobe with a well-defined homogenous solid mass. We restarted her on propanolol and referred her for a new course with methimazole. At the Policlinic University, she also underwent a left thyroid lobectomy. The resected lobe was sent for cytology evaluation which revealed a neoplastic nodule with features suggestive of a papillary thyroid cancer causing hyperthyroidism. The postoperative clinical progress of the patient was good and a regression of hyperthyroidism was also evidenced. Conclusions: The historical, clinical, and laboratory findings were suggestive of hyperthyroidism due to papillary thyroid cancer. A high index of suspicion, prompt referral, and counter-referral lead to a positive outcome of such a rare case. We advocate for systematic and careful evaluation of all thyroid nodules.