Thyroid & Adrenal
A 30-year-old woman has had recurrent episodes of headache and sweating. Her mother had renal calculi and died of thyroid cancer. Physical examination reveals a thyroid nodule but no clinical signs of thyroid dysfunction. Before performing thyroid surgery, the woman's physician should order
|A||A thyroid scan|
|B||Measurement of serum thyroid-releasing hormone and thyroid-stimulating hormone levels|
|C||Serial detenninations of serum calcium, phosphorus, protein, and alkaline phosphatase levels|
|D||Serial 24-h urine tests for catecholamine metanephrine. and vanillylmandelic acid excretion|
a. Diagnosis of MTC is established by history, physical examination, raised serum calcitonin or CEA levels, and FNA cytology of the thyroid mass.
b. Attention to family history is important because approximately 25% of patients with MTC have familial disease.
c. Because it is not possible to distinguish sporadic from familial disease at initial presentation, all new patients with MTC should be screened for RET point mutations, pheochromocytoma (24-hour urinary levels of VMA, catecholamine, and metanephrine), and hyperparathyroidism (serum calcium).
d. It is important to rule out a coexisting pheochromocytoma to avoid precipitating a hypertensive crisis and death.
e. Screening of patients with familial MTC for RET point mutations has largely replaced using provocation testing with pentagastrin or calcium-stimulated calcitonin levels to make the diagnosis.
f. Calcitonin and CEA are used to identify patients with persistent or recurrent MTC. Calcitonin is a more sensitive tumor marker, but CEA is a better predictor of prognosis