Question

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

Answer 1

1. Most anaplastic produce very little to no detectable thyroglobulin. So monitoring of TSH is ineffective in such type of cancers. Hence, option A is incorrect

Elevations in serum calcitonin is associated with medullary thyroid cancer. In papillary and follicular cancers serum thyroglobulin is elevated . Many of the thyroid cancer are TSH dependent, and thyroid hormone therapy is often prescribed to inhibit pitutary TSH secretion. Hence, Option B is incorrect

After thyroidectomy and removal of the most of the normal thyroid cells, blood levels of thyroglobulin fall and are often undetectable. Hence, option C is incorrect

Blood thyroglobulin levels are used to detect thyroid cancer recurrence, as an increase in thyroglobulin after thyroidectomy comes from thyroid cancer cells. Hence, Option D is the answer

2.Elevated Cardiac Troponin T has been reported significantly in patients with chronic renal failure.These levels do not seem to be affcted by hemodialysis, with elevations persisting after treatment. In chronic kideny disease patients without acute MI undergoing hemodilaysis, Cardiac troponin I has reported to have better sensitivty and specificity in detecting acute MI. But in patients with acute MI who have already diagnosed with chronic disease and undergoing dialysis treatmnet, Cardiac troponin T is highly sensitive to detect all cause mortality.Hence, Option B is the correct answer

Patients without acute MI, Cardica marker Troponin I is specific to detect myocardial ischemia, hence Option A is incorrect

Both markers are usable in dialysis patient. Hence, Option C is incorrect

Improper testing will affect the treatmnet options for the patinet and have increased mortality rate and additional burden for the client. hence, option D is incorrect