system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 40-year-old woman comes to the physician because of a small lump on the right side of her neck that she noticed while putting lotion on 1 week ago. She does not have any weight change, palpitations, or altered bowel habits. There is no family history of serious illness. Menses occur at regular 30-day intervals and lasts for 4 days. She appears well. Her temperature is 37°C (98.6° F), pulse is 88/min, and blood pressure is 116/74 mm Hg. Examination shows a small swelling on the right side of the neck that moves with swallowing. There is no lymphadenopathy. Ultrasound of the neck shows a 0.9-cm (0.35-in) right lobe thyroid mass with microcalcifications and irregular margins. Which of the following is the most appropriate next step in diagnosis?
assistant
Thyroid-stimulating hormone level