Endocrine—Thyroid Nodule
Concept
May be “hot” nodule, benign adenoma, malignancy, or other neck mass (parathyroid, lymph node)
Way Question May be Asked?
“31 y/o female seen by PMD recently for a sore throat was noted to have a mass in the left side of her thyroid. What do you want to do?” Could be presented with the mass found by a family MD and sent to you, could be given symptoms of hyperthyroidism. After your initial H + P, all patients get U/S and FNA.
How to Answer?
Complete H+P
Questions related to hyper or hypothyroidism Tachycardia
Heat intolerance Wt loss/gain Fatigue Depression Cold intolerance
History of radiation to neck (breast/Hodgkin’s) History of new hoarseness/changes in voice
Any possibility of MEN syndrome (ask of pheochro- mocytoma and hypercalcemia—about 10%
medullary’s associated with MEN)
Family history: goiter, MENII, thyroid cancer Diarrhea (medullary)
Physical Exam
Attention to description of the mass Cervical lymph nodes
Examination of vocal cords if new onset hoarseness Reflexes, pulse, BP (hyperthyroidism)
Diagnostic Tests
FNA—simple to perform in 1st office visit
U/S—helps look for other nodules, determine solid vs.
cystic
Thyroid scan (cold vs. hot nodule)
Blood tests: T4, TSH, thyroglobulin level (for f/u), thy- roid antibodies, calcitonin and Ca++level (if suspect medullary CA)
Be ready for Ca++to be elevated (change of scenario) If suspect pheo, get calcitonin, serum calcium, phos-
phate, urine studies for pheo, RET testing
Results of FNA
(1) Clear fluid, nodule disappears (observe and send fluid to pathology—surgery if large number of fol- licular particles)
(2) Clear fluid, nodule doesn’t disappear or recurs more than twice→surgery)
(3) Bloody fluid—fluid to pathology but pt goes to OR!
(4) Solid
(a) Clearly benign—thyroxin suppression for small 1 cm nodule non-toxic goiter, OR if nodule per- sists or enlarges over next 6 months
(b) Suspicious—follicular cells→ to OR
(c) Malignant—usually papillary as can can’t differentiate malignant follicular neoplasm except with final pathology showing capsular invasion
Surgical Treatment
Papillary CA
Young pt and tumor less than 2 cm→ lobectomy
54
Part 1.qxd 10/19/05 2:51 AM Page 54
All others get total thyroidectomy and removal of any obvious enlarged nodes This allows easy follow-up with radioactive iodine, thyroid scans and thyroglobulin levels
Follicular CA
Total thyroidectomy and sample any obvious nodes Medullary
Total thyroidectomy +
Central lymph node dissection (from larynx to suprasternal notch) and modified RND on side of palpable mass (if MEN, resect pheo first!) Anaplastic
Total thyroidectomy, if possible, if not, split gland to relieve any tracheal compression
Usually rapidly fatal Chemo/XRT
Know how to describe partial and total thyroidectomy and know your position on intra-op pathology con- sults of follicular adenoma (controversial)
Post-op
All pts get placed on Synthroid (enough to make TSH barely measurable)
Follow thyroglobulin levels (marker for recurrence) Stop thyroxin for 2 weeks six weeks post-op and do
total body radioactive I131 scan to detect any residual tumor for ablation
Repeat radioiodine scan q 6 months for next few years
Medullary Ca is followed by calcitonin levels and DMSA scan (nuclear medicine)
Common Curveballs
Be prepared for airway compromise post-op Be prepared for vocal cord paralysis post-op
Asked about possible nerve injuries (recurrent laryngeal and sup. laryngeal) and their consequences
Be prepared for hypocalcemia post-op Part of a MEN syndrome
Follicular cells on FNA
Justifying your reasoning for total thyroidectomy Will be nodules in both lobes
Will be goiter plus a nodule
Thyroglobulin levels will increase several months post-op Thyroid scan will show “hot nodule”
Strikeouts
Failing to rule out MEN syndrome
Not knowing how to deal with post-op complications Not performing FNA
Not knowing when to follow calcitonin levels (medullary carcinoma) and when to follow thy- roglobulin levels
Not performing central node dissection in medullary carcinoma
Not placing pt on thyroxin post-op and following TSH levels
Strikeouts 55
Part 1.qxd 10/19/05 2:51 AM Page 55
