20th August 2020

A 23-year-old woman took part in a research study and was found to have a hypoechoic mass

A 23-year-old woman took part in a research study and was found to have a hypoechoic mass on the ultrasound scan of her neck. Blood tests following the scan were done and revealed the following: 

T₄ 145mmol/L, TSH 0.7 mu/L, Na⁺ 140 mmol/L, K⁺ 4.1 mmol/L, Ca²⁺ 2.57 mmol/L, PTH 4 pmol/L, Glucose 5.2 mmol/L

For the patient above, please select the SINGLE most likely diagnosis based on the clinical history and/or biochemical tests provided. Select ONE option from the list above. 

You may use the following reference ranges:

• Serum total thyroxine, T₄: 70 – 140 mmol/L
• Serum Thyroid stimulating hormone, TSH: 0.5 – 5.7mu/L
• Serum sodium, Na⁺: 135 – 145mmol/L
• Serum potassium, K⁺: 3.5 – 5.0 mmol/L
• Serum total calcium, Ca²⁺: 2.12 – 2.65 mmol/L
• Serum parathyroid hormone, PTH: 2 – 7 pmol/L
• Serum (fasting) glucose: 4 – 6 mmol/L