thyroidectomy for thyroid cancer

Question 14

An adult woman has had a thyroidectomy for thyroid cancer. Eight weeks post-operatively while the patient is not being

treated orally with Na+-l-thyroxine (T4), thyroglobulin is measured. At this time the TSH is 50 mIU/mL (reference interval:

0.35 – 4.50 mIU/mL). Thyroglobulin is measured at 60 ug/L (reference interval: 2 – 44 ug/L). Which of the following

conditions could explain why the thyroglobulin is elevated?

		the patient’s thyroid tumor was an anaplastic thyroid carcinoma
		the patient’s thyroid tumor was a medullary thyroid carcinoma
		complete thyroidectomy was accomplished
		thyroid tissue is still present

Question 15

You offer troponin T (cTnT) testing in your laboratory. ED physicians call you complaining that cTnT is unusable in the diagnosis of acute myocardial infarction (AMI) in renal failure/dialysis patients because cTnT can be elevated in the absence of acute ischemia. Should you replace cTnT testing with cTnI testing?

		Yes – cTnI is less often elevated in renal dialysis pts than is cTnT
		Yes – cTnI is not elevated in renal dialysis pts except in the setting of myocardial ischemia or infarction
		No – neither marker is usable in dialysis patients
		No – use either marker and follow the pattern of change