Internal Medicine

0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22

1428 Thyroid Nodules and Cancer

■Partial thyroidectomy: follicular adenoma, small intrathyroidal pap-

illary CA, occasional anaplastic CA

■Total thyroidectomy: all other malignancies

■High-dose I-131 ablation: follicular/papillary CA 1 mo after total thy-

roidectomy when hypothyroid

follow-up

During Treatment

■Assess for hypocalcemia and hoarseness after total thyroidectomy

■Suppressive levothyroxine therapy after total thyroidectomy or I-131

ablation

Routine

■Adjust levothyroxine q 6–8 wks so that TSH completely suppressed

for follicular/papillary CA, or TSH normal for medullary/anaplastic

CA

■1 y after initial I-131 ablation: obtain serum thyroglobulin and whole

body I-131 scan after T4 levothyroxine withdrawal; repeat high-dose

I-131 ablation if thyroid CA still present

■Reiterate above process annually until thyroid CA no longer present;

may use thyrogen (human TSH) injection for evaluation; best evi-

dence for cure: undetectable serum thyroglobulin and negative I-131

whole body scan when serum TSH >30 mcU/mL or after thyrogen

injection

complications and prognosis

Complications

■Total thyroidectomy: hypothyroidism, hypoparathyroidism, recur-

rent laryngeal nerve injury

■Repeated I-131 ablation: hypothyroidism; leukemia (rare); radiation

fibrosis of lung for metastatic follicular/papillary CA

■Suppressive dose of levothyroxine T4: osteoporosis, cardiac toxi-

city

Prognosis

■Benign cysts/nodules: excellent

■Papillary/follicular CA: good

■Medullary CA: moderate

■Anaplastic CA: poor