Toxic Nodular Goiter Flashcards

1
Q

is TNG the most common cause of hyperthyroidism?

A

no, -it is 15-30% of hyperthyroid in US (2nd to grave’s)

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2
Q

In poor iodine diet areas, TNG is responsible for what percentage of hyperthyroidism

A

58%

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3
Q

What is the most common cause of hyperthyroidism in elderly and low dietary iodine

A

Toxic Nodular Goiter

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4
Q

is TNG more common in males or females?

A

females

F>M F5-7%, M1-2%

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5
Q

usual age of TNG diagnosis

A

Most >50 years old- lot of time has to do with mutation rate. You can have benign nodules and then overtime they can mutate and become functional- so in older age it can happen

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6
Q

Thyrotoxicosis occurs often after longstanding asymptomatic goiter once nodules become autonomous- peaks in what age?

A

50’s & 60’s

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7
Q

Symptoms of TNG

A
  • Can be Asymptomatic
  • Hyperthyroid related: Heat intolerance, palpitations, tremor, weight loss, ↑ amount of bowel movements
  • Compressive effects: dyspnea, hoarseness, dysphagia, (SVC syndrome- pt will have head edema)
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8
Q

Physical Exam of TNG

A
  • Tachycardia
  • Hyperkinesis
  • Moist skin
  • Tremor
  • Proximal muscle weakness- over time can have motor end plate damage which can result in muscle weakness and myopothy
  • increased DTRs (deep tendon reflexes)
  • Variable size of thyroid gland/nodules- size doesn’t translate with increase in symptoms
  • +/-hoarseness, +/-tracheal deviation
  • No ophthalmopathy, acropachy, pretibial myxedema! These are only in grave’s.
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9
Q

if there is phthalmopathy, acropachy, pretibial myxedema, could the patient have Toxic Nodular Goiter?

A
  • No ophthalmopathy, acropachy, pretibial myxedema! These are only in grave’s.
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10
Q

Toxic Nodular Goiter etiology

A
  • Related to iodine insufficiency- especially multinodular goiters, single adenomas tend to be due to mutations.
  • Deficiency → low T4- because thyroid needs iodine to produce T4, inducing hyperplasia to compensate
  • ↑cell replication increases risk of somatic mutations of TSH receptors, cell clone replication causing nodules
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11
Q

Toxic Nodular Goiter Labs

A
  • TSH low, T4/T3 elevated (similar to graves- but can run autoantibodies to graves and can tell difference between the two)
  • If isolated T4 elevation- could be due to medications that reduce conversion of T4 to T3: propranolol, corticosteroids, radiocontrast, amiodarone)- remember T4 is precursor to T3
  • Subclinical hyperthyroidism: low TSH, normal T4/T3 levels= pts are typically asymptomatic
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12
Q

Toxic Nodular Goiter Imaging

A

Nuclear scintigraphy (iodine uptake imaging)

  • Grave’s: homogenous diffuse uptake
  • Tyroiditis: low uptake
  • TNG: usually patchy uptake
  • Can also show substernal extension of the thyroid gland- with uptake imaging you can pick this up

If compressive symptoms: CT, don’t put this off- do this quickly especially if airway compression

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13
Q

would Cold nodules or hot nodules on Nuclear scintigraphy be concerning?

A

cold nodules

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14
Q

Toxic Nodular Goiter will look like what in Nuclear scintigraphy?

A

very patchy because nodules in different places

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15
Q

Why are old nodules on Nuclear scintigraphy concerning?

A

sign of malignancy

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16
Q

would you do fine needle aspiration on a hot nodule?

A

FNA not usually needed for “HOT” nodule (autonomously functioning nodule)- risk is low malignancy

17
Q

would you do fine needle aspiration on a cold nodule?

A

yes

18
Q

TNG treatment

A

Surgery or Radioactive iodine-requires definitive treatment

19
Q

if pt has compressive symptoms then need to do _______.

A

surgery

20
Q

Complications from Radioactive Iodine

A
  • Less occurrence of Hypothyroidism than Grave’s: only 10-20%
  • Could get radiation induced thyroiditis (rare)
  • Thyroid storm, very rare (from rapidly enlarging goiter)- pretreat with antithyroids
  • Role of anti-thyroids/BB: short courses to get patient euthyroid before radiation/surgery, after radiation while thyrotoxic until full response from radiation
  • not as immediate of a response as surgery, takes a little time
21
Q

Indications for surgery in toxic nodular goiter

A
o	Young
o	Large nodules
o	Compressive symptoms
o	Non-functioning/suspicious nodules
o	Pregnant
o	Radiation failure
-	Total or near total cure 90% (rapid relief)
-	Recurrence less likely than in subtotal- total thyroidectomy will have less recurrence rate than subtotal.
22
Q

Surgery Complications in toxic nodular goiter

A
  • Hypothyroid
  • Vocal cord paralysis
  • Hypoparathyroidism
  • Post op bleed- every surgery has this risk
  • Infection- every surgery has this risk
23
Q

toxic nodular goiter patient care information

A
  • Radiation may take 10 weeks to achieve clinical response
  • Levothyroxine started after thyroidectomy , re-evalaluation after 4-6 weeks. (Subtotal thyroidectomy doesn’t necessarily need it)
  • Subclinical hyperthyroid checked biochemically every 6 months- go through ROS to make sure there isn’t any thyroid symptoms
24
Q

toxic nodular goiter prognosis

A
  • Treated= good
  • Untreated=much worse
  • Leads to Osteoporosis, dysrhythmias, HF, death
25
Q

In toxic nodular goiter, autonomously functioning thyroid nodules result in ______.

A

hyperthyroidism