Hypothyroidism Quiz: Ace Your Exams

A 31-year-old man comes to the PA complaining of neck pain for the past week. The pain is located mainly in the neck, but states that it travels to the jaw at times. He experienced episodes of palpitations and anxiety-attacks for several weeks, which resolved spontaneously one week ago. Past medical history is significant for Crohn disease, which is well-managed with diet. The patient’s father had thyroid cancer at the age of 77. Temperature is 37.0°C (98.6°F), pulse is 82/min, blood pressure is 124/88 mm Hg, and BMI is 20 kg/m². Palpation of the neck causes severe pain for the patient. The thyroid gland is asymmetrically enlarged. Laboratory studies show the following:  

Laboratory value	Result	Reference Range
Sodium	137 mEq/L	136-146 mEq/L
Potassium	4.8 mEq/L	3.5-5 mEq/L
Chloride	99 mEq/L	95-105 mEq/L
Creatinine	0.6 mg/dL	0.6-1.2 mg/dL
Glucose	89 mg/dL	70-110 mg/dL
ESR	46 mm/h	0-15 mm/hr
TSH	6.8 μU/mL	0.5-5 μU/mL
Anti-thyroid peroxidase	Negative	Negative
Anti-thyroglobulin antibody	Negative	Negative

A biopsy of the thyroid gland is performed and shows diffuse infiltration with lymphocytes and giant cells forming noncaseating granulomas, as well as disruption and collapse of thyroid follicles. Further evaluation of this patient will most likely reveal which of the following?