A 78-year-old man comes to the emergency department due to palpitations, dizziness, and shortness of breath. He has had intermittent palpitations over the past 3-4 weeks, with constant symptoms for the last 2 days. In addition, the patient has had dyspnea with mild exertion and feels fatigued "all the time." He has also experienced unexpected weight loss over the last few months, but has had no neck pain, fever, nausea, abdominal pain, chest pain, motor weakness, or loss of consciousness. Medical history is significant for hypertension, which has been treated with valsartan and hydrochlorothiazide for the past 12 years. The patient also takes a fish oil capsule daily "to support my heart health," although he has had difficulty lately swallowing the large capsules. He is married and does not use tobacco or alcohol. Blood pressure is 130/80 mm Hg and pulse is 120/min and irregular. Thyroid examination shows a 3-cm nodule in the right thyroid lobe. Eye examination reveals no lid lag or proptosis. The heart has an irregular tachycardia with no murmurs. ECG shows atrial fibrillation with rapid ventricular response and nonspecific T-wave abnormalities. Laboratory results are as follows: Thyroid ultrasound reveals a 2.8-cm right-sided hyperechoic nodule. Radioactive iodine uptake is 55% at 24 hours (normal: 5%-30%), and scan shows increased uptake in the right thyroid nodule, with the rest of the gland showing reduced uptake. The patient is started on metoprolol and an oral anticoagulant and reports improvement in his palpitations. Which of the following is the most appropriate next step in management of this patient's thyroid condition?
A)Fine-needle aspiration biopsy
B)Methimazole
C)Propylthiouracil
D)Radioactive iodine ablation
E)Thyroidectomy

Question

A 78-year-old man comes to the emergency department due to palpitations, dizziness, and shortness of breath.  He has had intermittent palpitations over the past 3-4 weeks, with constant symptoms for the last 2 days.  In addition, the patient has had dyspnea with mild exertion and feels fatigued "all the time."  He has also experienced unexpected weight loss over the last few months, but has had no neck pain, fever, nausea, abdominal pain, chest pain, motor weakness, or loss of consciousness.  Medical history is significant for hypertension, which has been treated with valsartan and hydrochlorothiazide for the past 12 years.  The patient also takes a fish oil capsule daily "to support my heart health," although he has had difficulty lately swallowing the large capsules.  He is married and does not use tobacco or alcohol.  Blood pressure is 130/80 mm Hg and pulse is 120/min and irregular.  Thyroid examination shows a 3-cm nodule in the right thyroid lobe.  Eye examination reveals no lid lag or proptosis.  The heart has an irregular tachycardia with no murmurs.  ECG shows atrial fibrillation with rapid ventricular response and nonspecific T-wave abnormalities.  Laboratory results are as follows:  Thyroid ultrasound reveals a 2.8-cm right-sided hyperechoic nodule.  Radioactive iodine uptake is 55% at 24 hours (normal: 5%-30%), and scan shows increased uptake in the right thyroid nodule, with the rest of the gland showing reduced uptake.  The patient is started on metoprolol and an oral anticoagulant and reports improvement in his palpitations.  Which of the following is the most appropriate next step in management of this patient's thyroid condition?
A)Fine-needle aspiration biopsy 
B)Methimazole 
C)Propylthiouracil 
D)Radioactive iodine ablation 
E)Thyroidectomy

Quizplus · Accepted Answer

Explanation: 11ec2b69_c139_be59_8f63_6140a2a78aac_MD0005_00 This patient has symptomatic hyperthyroidism (increased serum thyroxine, suppressed TSH). In addition, he has increased radioiodine uptake in a large thyroid nodule with suppressed uptake in the remainder of the gland. These are characteristic features of a toxic thyroid nodule (toxic adenoma). Although beta blockers (eg, metoprolol, atenolol) can provide symptomatic relief in patients with toxic adenoma, definitive therapy with either radioactive iodine ablation or surgery (eg, hemithyroidectomy) is required to achieve permanent euthyroidism. However, prior to definitive therapy, patients may need to be pretreated with antithyroid drugs (eg, methimazole) to achieve chemical euthyroidism. Pretreatment is advised for all patients undergoing surgery; it is also recommended prior to radioiodine therapy for older patients and those with significant cardiovascular risk factors (eg, diabetes, known coronary artery disease). (Choice A) Biopsy of hyperfunctioning nodules is not necessary as the risk of cancer in these nodules is very low. (Choice C) Methimazole is preferred over propylthiouracil (PTU) for most patients due to the risk of severe hepatotoxicity with PTU. PTU is preferred if hyperthyroidism is diagnosed in the first trimester of pregnancy as methimazole is associated with more severe teratogenic effects. (Choices D and E) Surgery is preferred over radioactive iodine ablation for patients with very large goiters, obstructive symptoms (eg, dysphagia, as in this patient), suspected thyroid cancer, or contraindications to radioiodine (eg, breastfeeding). However, this patient requires pretreatment prior to definitive therapy. Educational objective: Toxic thyroid nodules are characterized by increased radioiodine uptake in the nodule and suppressed uptake in the remainder of the gland. Definitive treatment with surgery or radioactive iodine ablation is recommended for patients with overt hyperthyroidism; surgery is preferred for those with large goiters, obstructive symptoms, or suspected thyroid cancer. Patients should be treated with antithyroid drugs to achieve euthyroidism prior to surgery; methimazole is preferred over propylthiouracil for most patients. References: 2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. (http://www.ncbi.nlm.nih.gov/pubmed/27521067)

A 78-Year-Old Man Comes to the Emergency Department Due to Palpitations