Megan%20Chan,%20PGY-1

1
Thyroid Cases

• Megan Chan, PGY-1
• UHCMC 2015

2
Guess the Diagnosis?
TSH Free T4 T3 Diagnosis
? ? ? Primary hyperthyroidism
? ? ? Central hyperthyroidism
? Normal Normal Subclinical hyperthyroidism
? Normal ? T3 thyrotoxicosis
? ? ? Primary hypothyroidism
? ? ? Central hypothyroidism
? Normal Normal Subclinical hypothyroidism
Normal ? ? Exogenous thyroid hormone
3
Case 1

• 44 y/o male is involved in a motor vehicle
  collision and sustains multiple injuries to the
  face, chest and plevis. He is unresponsive on
  the field and is intubated for airway protection.
  Pt is admitted to the ICU, stabilized and
  undergoes successful open reduction internal
  fixation of the right femur and right humerus.
  After he returns to the ICU, his TSH is 0.3 mU/L
  and the total T4 level is normal. T3 is 0.6
  µg/dL.
• What is the most appropriate next management
  step?
• Initiation of levothyroxine
• Radionucleotide uptake scan
• Thyroid ultrasound
• Observation
• Initiation of prednisone

4
Case 1

• What is the most appropriate next management
  step?
• Initiation of levothyroxine
• Radionucleotide uptake scan
• Thyroid ultrasound
• Observation
• Initiation of prednisone
• Sick-euthyroid syndrome can occur in any acute,
  severe illness. TSH/T4/T3 abnormalities are
  thought to result from release of cytokines in
  response to severe stress. The most common
  hormone pattern is low total and unbound T3 as
  peripheral conversion of T4 to T3 is impaired.
  This is thought to be evolutionarily helpful as
  lowering the most active thyroid hormone would
  limit catabolism in starved or ill patients. T4
  may be decreased in very sick patients. Thyroid
  function will return to normal in weeks to months
  as the patient recovers.

5
Case 2

• 29 y/o woman presents to your clinic complaining
  of difficulty swallowing, sore throat, and tender
  swelling in her neck. She has also noted fevers
  intermittently over the past week. Several weeks
  prior to her current symptoms she experienced
  symptoms of an URI. She has no PMHx. On exam, she
  is noted to have a small goiter that is painful
  to the touch. Her oropharynx is clear. Labs
  show WBC of 14.1 with normal diff, ESR 53, TSH of
  21. Thyroid antibodies are negative.
• What is the most likely diagnosis?
• Autoimmune hypothyroidism
• Cat-scratch fever
• Ludwigs angina
• Subacute thyroiditis

6
Case 2

• What is the most likely diagnosis?
• Autoimmune hypothyroidism
• Cat-scratch fever
• Ludwigs angina
• Subacute thyroiditis
• What is the most appropriate treatment for this
  patient?
• Iodine ablation of the thyroid
• Large doses of Aspirin
• Local radiation therapy
• No treatment necessary
• Propylthiouracil

7
Case 2

• What is the most appropriate treatment for this
  patient?
• Iodine ablation of the thyroid
• Large doses of Aspirin
• Local radiation therapy
• No treatment necessary
• Propylthiouracil

8
Subacute Thyroiditis

• Aka Quervains thyroiditis, granulomatous
  thyroiditis, viral thyroiditis
• Presents with fever, constitutional symptoms,
  painful enlarged thyroids.
• Peak incidence 30-50 y/o, females gt males
• Multiple viruses have been implicated, but none
  identified as the trigger
• 3 phase illness
• 1st Thyroid inflammation ? follicle destruction
  ? release of thyroid hormones ? Thyrotoxicosis
• Low TSH, high T4 T3, radioiodine uptake is
  low/undetectable.
• 2ndThyroid is depleted of hormone ?
  Hypothyroidism
• Elevated TSH, low free T4, radioiodine uptake
  returns to normal.
• 3rdRecovery phase decreased inflammation ?
  follicles heal regenerate thyroid hormone (4-6
  months later)
• Usually self-limited, benign
• Treatment
• Mild sxs Large doses of Aspirin (600mg q4-6hrs),
  NSAIDs
• Severe sxs Steroid taper
• May require low-dose levothyroxine

9
Case 3

• 62 y/o man presents to the ED with chest pressure
  and feeling like my heart is fluttering inside
  my chest. He experienced similar symptoms 1
  month ago that resolved spontaneously. He did
  not seek medical attention at that time. He has
  no significant PMHx. On ROS he notes some recent
  weight loss despite an increase in appetite and
  excessive sweating. On exam, HR is irregular at
  140-150 beats/min. BP is 135/55. He is admitted
  and screening tests reveal and undetectable TSH
  level.

10
Case 3

• Which of the following statements is true?
• 50 of hyperthyroid patients will convert from
  Afib to NSR with thyroid management alone.
• A firm, small thyroid on exam would be compatible
  with a diagnosis of Graves disease.
• Afib is the most common cardiac manifestation of
  hyperthyroidism.
• His excessive sweating is likely not related to
  hyperthyroidisim.
• Hyperthyroidism leads to a high-output state for
  the heart, narrowing the pulse pressure.

11
Case 3

• Which of the following statements is true?
• 50 of hyperthyroid patients will convert from
  Afib to NSR with thyroid management alone.
• A firm, small thyroid on exam would be compatible
  with a diagnosis of Graves disease.
• Afib is the most common cardiac manifestation of
  hyperthyroidism.
• His excessive sweating is likely not related to
  hyperthyroidisim.
• Hyperthyroidism leads to a high-output state for
  the heart, narrowing the pulse pressure.
• Common signs of thyrotoxicosis include
  tachycardia (most common cardiac abnormality),
  Afib, tremor, goiter, and warm, moist skin.
  Common symptoms include hyperactivity, dysphoria,
  irritability, heat intolerance, excessive
  sweating and fatigue. Weight loss occurs
  frequently however, some pts will gain weight as
  they typically have marked increase in appetite.
  The arrhythmias are a manifestation of a
  high-output state, which frequently leads to a
  widened pulse pressure and a systolic murmur.
  This can exacerbate underlying heart failure or
  CAD.

12
Case 3

• The same patient is started on atenolol and his
  heart rate slows to 80 beats/min.
• Which of the following additional therapies is
  most indicated?
• Diltiazem
• Methimazole
• Levothyroxine
• Liothyronine
• Phenoxybenzamine

13
Case 3

• Which of the following additional therapies is
  most indicated?
• Diltiazem
• Methimazole
• Levothyroxinesometimes used in combination with
  antithyroid drugs (block-replace regimen) to
  avoid drug-induced hypothyroidism.
• Liothyronine (oral form of T3)
• Surgical resection
• Hyperthyroidism is treated with antithyroid
  drugs, radioactive iodine, or thyroidectomy.
  Methimazole and PTU inhibit thyroid peroxidase
  and thus decrease production of T4 T3. In
  Graves disease, they also reduce thyroid
  antibody levels. Thyroid function tests
  clinical manifestations are reviewed every 3-4
  weeks with dose titrated based on unbound T4.
  Euthyroidism usually takes 6-8 weeks.

14
Case 4

• 40 y/o female with Graves disease was recently
  started on methimazole. One month later she comes
  to clinic for a routine follow up. She notes
  some low-grade fevers, arthralgia, and general
  malaise. Labs show mild transaminitis and
  glucose of 150.
• All of the following are known side effects of
  methimazole except
• Agranulocytosis
• Rash
• Arthralgias
• Hepatitis
• Insulin resistance

15
Case 4

• All of the following are known side effects of
  methimazole except
• Agranulocytosis
• Rash
• Arthralgias
• Hepatitis
• Insulin resistance
• Methimazole and PTU both inhibit the function of
  thyroid peroxidase, reducing oxidation and
  organification of iodide. Rash, urticaria, fever
  arthralgias are common side effects. Major
  side effects are rare but include hepatitis,
  agranulocytosis (lt1) SLE-like syndrome.

16
Case 5

• A patients presents to clinic with complaints of
  fatigue hair loss. He has gained 6.4kg since
  his last clinic visit 6 months ago but notes
  markedly decreased appetite. On ROS, he reports
  not sleeping well feels cold all the time. He
  is still able to enjoy his hobbies and does not
  believe that he is depressed. Exam reveals
  diffuse alopecia and slowed deep tendon reflex
  relaxation.

17
Case 5

• Which of the following statements regarding the
  most likely diagnosis is correct?
• A normal TSH excludes secondary, but not primary
  hypothyroidism.
• T3 measurement is not indicated to make the
  diagnosis.
• The T3/T4 ratio is important for determining
  response to therapy.
• Thyroid peroxidase antibodies distinguish between
  primary and secondary hypothyroidism.
• Unbound T4 is a better screening test than TSH
  for subclinical hypothyroidism.

18
Case 5

• Which of the following statements regarding the
  most likely diagnosis is correct?
• A normal TSH excludes secondary, but not primary
  hypothyroidism.
• T3 measurement is not indicated to make the
  diagnosis.
• The T3/T4 ratio is important for determining
  response to therapy.
• Thyroid peroxidase antibodies distinguish between
  primary and secondary hypothyroidism.
• Unbound T4 is a better screening test than TSH
  for subclinical hypothyroidism.
• While hypothyroidism may be strongly suspected
  from history physical exam, it is definitively
  diagnosed with labs. TSH should be the first
  test sent. A normal TSH excludes primary, but
  not secondary, hypothyroidism. T3 levels are
  normal in 25 of patients with clinical
  hypothyroidism and not indicated for diagnosis.
  T3/T4 ratio is not helpful for diagnosis or
  prognosis. If TSH is low or normal pituitary
  disease is suspected, a free T4 should be sent.
  If T4 is low, DDx includes anterior pituitary
  dysfxn, sick euthyroid syn, drug effects. In
  subclinical hypothyroidism, TSH is the test of
  choice as TSH is elevated and T4 in normal.
  Thyroid peroxidase antibodies are present in gt90
  of patients with autoimmune hypothyroidism.

19
(No Transcript)
20
Case 6

• A 75 y/o woman is diagnosed with hypothyroidism.
  She has long-standing CAD and is wondering about
  the potential consequences for her cardiovascular
  system.
• Which of the following statements is true
  regarding the interaction of hypothyroidism and
  the CV system?
• Myocardial contractility is increased with
  hypothyroidism.
• A reduced stroke volume is found with
  hypothyroidism.
• Pericardial effusions are rare manifestations of
  hypothyroidism.
• Reduced peripheral resistance is found in
  hypothyroidism and may be accompanied by
  hypotension.
• Blood flow is diverted toward the skin in
  hypothyroidism.

21
Case 6

• Which of the following statements is true
  regarding the interaction of hypothyroidism and
  the CV system?
• Myocardial contractility is increased with
  hypothyroidism.
• A reduced stroke volume is found with
  hypothyroidism.
• Pericardial effusions are rare manifestations of
  hypothyroidism.
• Reduced peripheral resistance is found in
  hypothyroidism and may be accompanied by
  hypotension.
• Blood flow is diverted toward the skin in
  hypothyroidism.
• Hypothyroidism is associated with bradycardia
  reduced myocardial contractility, thereby
  reducing stroke volume. Increase peripheral
  resistance may be accompanied by diastolic
  hypertension. Pericardial effusions are found in
  up to 30 of patients. Blood flow is directed
  away from the skin thus produce cool
  extremities.

22
Case 7

• 38 y/o woman presents to clinic complaining of
  fatigue irritability that have been worsening
  over the past several months. She has a history
  of mild intermittent asthma and
  hypertriglyceridemia. Exam reveals HR 105, BP
  136/72, bilateral proptosis and warm, moist skin.
  Screening tests are sent and reveal a TSH level
  that is undetectable and a normal free T4.
• What should be the next step in diagnosis?
• Radionuclide scan of the thyroid
• Thyroid-stimulating antibody screen
• Thyroid peroxidase antibody screen
• Total T4
• Unbound T3

23
Case 7

• What should be the next step in diagnosis?
• Radionuclide scan of the thyroid
• Thyroid-stimulating antibody screen
• Thyroid peroxidase antibody screen
• Total T4
• Unbound T3
• In patients with thyrotoxicosis due to Graves
  disease, the TSH is low and total unbound
  thyroid hormone levels are increased. In 2-5 of
  patients, only the T3 levels will be increased.
  In this patient with a high pre-test probability
  of Graves disease, a suppressed TSH normal T4
  supports Graves however, T3 should be tested to
  definitively make the diagnosis. Measuring
  thyroid antibodies will help confirm the
  diagnosis of Graves but the diagnosis can be
  made without them. Radionuclide scan is used to
  evaluate for toxic multinodular goiter and toxic
  adenoma.

24
(No Transcript)
25
Case 8

• Which of the following is most consistent with a
  diagnosis of subacute thyroiditis?
• 38 y/o female with 2-wk history of painful
  thyroid, elevated T4 T3, low TSH, and an
  elevated radioactive iodine uptake scan.
• 42 y/o male with history of painful thyroid 4
  months ago, fatigue, malaise, low free T4 T3,
  and elevated TSH.
• 31 y/o female with a painless enlarged thyroid,
  low TSH, elevated T4 free T4, and an elevated
  radioactive iodine uptake scan.
• 50 y/o male with a painful thyroid, slightly
  elevated T4, normal TSH, and an ultrasound
  showing a mass.
• 46 y/o female with 3 weeks of fatigue, low T4
  T3, and low TSH.

26
Case 8

• Which of the following is most consistent with a
  diagnosis of subacute thyroiditis?
• 38 y/o female with 2-wk history of painful
  thyroid, elevated T4 T3, low TSH, and an
  elevated radioactive iodine uptake scan.
• 42 y/o male with history of painful thyroid 4
  months ago, fatigue, malaise, low free T4 T3,
  and elevated TSH.
• 31 y/o female with a painless enlarged thyroid,
  low TSH, elevated T4 free T4, and an elevated
  radioactive iodine uptake scan.
• 50 y/o male with a painful thyroid, slightly
  elevated T4, normal TSH, and an ultrasound
  showing a mass.
• 46 y/o female with 3 weeks of fatigue, low T4
  T3, and low TSH.
• Recall the 3 stages of subacute thyroiditis
• 1) ThyrotoxicosisLow TSH, high T4 T3,
  radioiodine uptake is low/undetectable.
• 2) HypothyroidismElevated TSH, low free T4,
  radioiodine uptake returns to normal.
• 3) Recovery (4-6 months later)
• Patient B is in the hypothyroid stage of subacute
  thyroiditis.
• Patient A is consistent with the thyrotoxic phase
  except the radioiodine uptake scan should be
  decreased, not elevated.
• Patient C is more consistent with Graves
  disease.
• Patient D is consistent with neoplasm.
• Patient E is consistent with central
  hypothyroidism.

27
Case 9

• A healthy 53 y/o man comes to your office for an
  annual physical exam. He has no complaints and
  has no significant medical history. He is taking
  an OTC multivitamin and no other medications. On
  exam he is noted to have a nontender thyroid
  nodule. His TSH is found to be low.
• What is the next step in his evaluation?
• Close follow-up and measure TSH in 6 months.
• Fine-needle aspiration
• Low-dose thyroid replacement
• PET followed by surgery
• Radionuclide thyroid scan

28
Case 9

• What is the next step in his evaluation?
• Close follow-up and measure TSH in 6 months.
• Fine-needle aspiration
• Low-dose thyroid replacement
• PET followed by surgery
• Radionuclide thyroid scan
• Thyroid nodules are found in 5 of patients and
  are more common with age, in women, and in
  iodine-deficient areas. TSH should be the first
  test after detection of a thyroid nodule. In the
  case of normal TSH, FNA or US-guided biopsy
  should be pursued. If the TSH is low, a
  radionuclide scan should be performed to
  determine if the nodule is the source of thyroid
  hyperfunction. Hot nodules can be treated
  medically, resected or ablated with radioactive
  iodine. Cold nodules should undergo FNA. 4
  of nodules will be malignant, 10 suspicious for
  malignancy 86 are indeterminate or benign.

29
(No Transcript)
30
Case 10

• 38 y/o mother of three presents to her PCP with
  complaints of fatigue and low energy for 3
  months. She was previously healthy and was
  taking no medications. She does report a 5kg
  weight gain and severe constipation, for which
  she is now taking laxatives. A TSH is elevated at
  25 mU/L. Free T4 is low. She is wondering why
  she has hypothyroidism.
• Which of the following tests is most likely to
  diagnose the etiology?
• Antithyroglobulin antibiody
• Antithyroid peroxidase antibody
• Radioiodine uptake scan
• Serum thyroglobulin level
• Thyroid ultrasound

31
Case 10

• Which of the following tests is most likely to
  diagnose the etiology?
• Antithyroglobulin antibiody
• Antithyroid peroxidase antibody (TPO)
• Radioiodine uptake scan
• Serum thyroglobulin level
• Thyroid ultrasound
• The most common cause of hypothyroidism in the US
  is autoimmune thyroiditis, as it is a
  iodine-replete area. Although earlier in the
  disease, a radiooidine uptake scan may have shown
  diffusely increased uptake from lymphocytic
  infiltration, at this point in the disease when
  the infiltrate is burned out there is likely to
  be little found on the scan. Likewise, a thyroid
  ultrasound would only be useful for presumed
  multinodular goiter. TPO Abs are commonly found
  in autoimmune thyroditis, while antithyroglobulin
  Abs are less commonly found. Antithyroglobulin
  Abs are also found in other thyroid disorders
  (Graves disease, thyrotoxicosis) and systemic
  autoimmune diseases (SLE). Thyroglobulin is
  released from the thyroid in all types of
  thyrotoxicosis with the exception of thyroid
  disease. This patient, however, is hypothyroid.

32
Case 11

• A 54 y/o woman with long-standing hypothyroidism
  is seen by her PCP for a routine evaluation. She
  reports feeling fatigues and somewhat
  constipated. Since her last visit, her other
  medical conditions, which include
  hypercholesterolemia systemic HTN, are stable.
  She was diagnosed with uterine fibroids and
  started on iron recently. Her other meds include
  levothyroxine, atorvastatin, and HCTZ. Her TSH
  is found to be elevated at 15 mU/L. Which of the
  following is the most likely reason for her
  elevated TSH?
• Celiac disease
• Colon cancer
• Medication noncompliance
• Poor absorption of levothyroxine due to ferrous
  sulfate
• TSH-secreting pituitary adenoma

33
Case 11

• Which of the following is the most likely reason
  for her elevated TSH?
• Celiac disease
• Colon cancer
• Medication noncompliance
• Poor absorption of levothyroxine due to ferrous
  sulfate
• TSH-secreting pituitary adenoma
• An increase in TSH in a patient with
  hypothyroidism that was previously stable in
  dosing for many years suggests either a failure
  of taking the medication, difficulty with
  absorption from bowel disease, or medication
  interaction. Pts with normal body weight taking
  gt200µg of levothyroxine per day with continued
  elevated TSH strongly suggests noncompliance.
  Other causes of increased thyroxine requirements
  include malabsorption (celiac disease, small
  bowel resection), estrogen therapy, drugs that
  interfere with T4 absorption (ferrous sulfate,
  cholestyramine) or clearance (lovastatin,
  amiodarone, carbamazepine, phenytoin).

34
Case 12

• 87 y/o woman is admitted to the MICU with
  depressed level of consciousness, hypothermia,
  sinus bradycardia, hypotension and hypoglycemia.
  She was previously healthy with the exception of
  hypothyroidism and systemic HTN. Her family mends
  that she was not taking any of her medications
  due to financial difficulties. There is no
  evidence of infection on exam, urine microscopy,
  or CXR. Her labs are notable for mild
  hyponatremia and glucose of 48. TSH is gt100
  mU/L.

35
Case 12

• All of the following statements regarding this
  condition are true EXCEPT
• External warming is a critical feature of therapy
  in patients with a temperature above 34º C.
• Hypotonic IV solutions should be avoided.
• IV levothyroxine should be administered with IV
  glucocorticoids.
• Sedation should be avoided if possible.
• This condition occurs almost exclusively in the
  elderly and often is precipitated by an unrelated
  medical illness.

36
Case 12

• All of the following statements regarding this
  condition are true EXCEPT
• External warming is a critical feature of therapy
  in patients with a temperature above 34º C.
• Hypotonic IV solutions should be avoided.
• IV levothyroxine should be administered with IV
  glucocorticoids.
• Sedation should be avoided if possible.
• This condition occurs almost exclusively in the
  elderly and often is precipitated by an unrelated
  medical illness.
• The patient has myxedema coma. This condition of
  profound hypothyroidism most commonly occurs in
  the elderly, often with a precipitating condition
  (e.g. MI, infection). Management includes IV
  levothyroxine and glucocorticoids due to impaired
  adrenal reserve in severe hypothyroidism. Care
  must be taken with rewarming as it may
  precipitate cardiovascular collapse. Therefore,
  external warming is indicated only if temperature
  is below 30ºC. Hypertonic saline glucose may be
  used if hyponatremia or hypoglycemia is severe
  however hypotonic solutions should be avoided as
  this may worsen fluid retention.

37
Case 13

• 29 y/o woman is evaluated for anxiety,
  palpitations, and diarrhea and is found to have
  Graves disease. Before she begins therapy for
  her thyroid condition, she has an episode of
  acute chest pain and presents to the ED. Although
  a CT angiogram is ordered, the radiologist calls
  to notify the treating physician that this is
  potentially dangerous.

38
Case 13

• Which of the following best explains the
  radiologists recommendation?
• Pulmonary embolism is exceedingly rare in Graves
  disease.
• Radiation exposure in patients with
  hyperthyroidism is associated with increased risk
  of subsequent malignancy.
• Iodinated contrast exposure in patients with
  Graves disease may exacerbate hyperthyroidism.
• Tachycardia with Graves disease limits the image
  quality of CT angiography and will not allow
  accurate assessment of pulmonary embolism.
• The radiologist was mistaken CT angiography is
  safe in Graves disease.

39
Case 13

• Which of the following best explains the
  radiologists recommendation?
• Pulmonary embolism is exceedingly rare in Graves
  disease.
• Radiation exposure in patients with
  hyperthyroidism is associated with increased risk
  of subsequent malignancy.
• Iodinated contrast exposure in patients with
  Graves disease may exacerbate hyperthyroidism.
• Tachycardia with Graves disease limits the image
  quality of CT angiography and will not allow
  accurate assessment of pulmonary embolism.
• The radiologist was mistaken CT angiography is
  safe in Graves disease.
• Pts with Graves disease produce
  thyroid-stimulating immunoglobulins. They
  subsequently produce higher levels of T4 compared
  with the normal population. As a result, many
  patients with Graves disease are mildly iodine
  deficient, and T4 production is somewhat limited
  by the availability of iodine. Exposure to
  iodinated contrast thus reverse iodine deficiency
  and may precipitate worsening hyperthyroidism.
  Additionally, the reversal of mild iodine
  deficiency may make I-125 therapy for Graves
  disease less successful because thyroid iodine
  uptake is lessened in the iodine-replete state.

40
Case 14

• Which of the following statements best describes
  Graves ophthalmopathy?
• Although a cosmetic problem, Graves
  ophthalmopathy is rarely associated with major
  ocular complications.
• Diplopia may occur from periorbital muscle
  swelling.
• It is never found without concomitant
  hyperthyroidism.
• The most serious complication is corneal
  abrasion.
• Unilateral disease is not found.

41
Case 14

• Which of the following statements best describes
  Graves ophthalmopathy?
• Although a cosmetic problem, Graves
  ophthalmopathy is rarely associated with major
  ocular complications.
• Diplopia may occur from periorbital muscle
  swelling.
• It is never found without concomitant
  hyperthyroidism.
• The most serious complication is corneal
  abrasion.
• Unilateral disease is not found.
• Although lid retraction can occur in any type of
  hyperthyroidism, Graves disease is associated
  with specific eye signs that are thought to be
  due to the interaction of autoantibodies within
  the periorbital muscles. The onset of Graves
  ophthalmopathy may occur before or after
  hyperthyroidism, and rarely may not be associated
  with hyperthyroidism at all. Proptosis occurs in
  1/3 of patients and may result in corneal
  abrasion if there is failure of closure of the
  eyelids, esp during sleep. However, the most
  serious manifestation is compression of the optic
  nerve at the apex of the orbit, which can lead to
  papilledema and permanent vision loss if left
  untreated.

42
Case 15

• 23 y/o woman is evaluated for a 2 week history of
  nervousness, palpitations, nausea, vomiting and
  weight loss. She is 3 weeks pregnant and says she
  was previously in excellent health. The patient
  takes a daily prenatal multivitamin but no other
  prescription medication, iodine supplement or
  other OTC meds.
• On exam BP 130/79, HR 110 and regular. Cardiac,
  lung, and eye exam are normal. The thyroid gland
  shows a significantly enlarged gland with a soft
  bruit but no nodules. No neck tenderness.
  Abdominal exam reveals a 2cm patch of vitiligo.
  A fine bilateral hand tremor and warm, moist skin
  are noted. No evidence of pretibial myxedema.

43
Case 15

• Labs
• CBC CMP normal
• TSH lt 0.01, Free T4 4.0 (high), Free T3 6
  (high)
• Human chorionic gonadotropin positive
• Thyroid peroxidase Ab 40 units/L (normal is lt20)
• Thyroid stimulating Ab 140 (normal is lt130)
• Which of the following is the most appropriate
  initial treatment?
• Methimazole
• Propylthiouracil
• Thyroidectomy
• Reassurance

44
Case 15

• Which of the following is the most appropriate
  initial treatment?
• Methimazole
• Propylthiouracil
• Thyroidectomy
• Reassurance
• In pregnant women, untreated hyperthyroidism is
  associated with an increased risk of miscarriage,
  fetal growth retardation, premature delivery, and
  preeclampsia. This patient has autoimmune Graves
  hyperthyroidism and should receive
  propylthiouracil while in the 1st trimester of
  pregnancy. She can switch to methimazole in the
  2nd 3rd trimesters, at which time there is
  decreased risk of fetal abnormalities (e.g.
  aplasia cutis, choanal atresia) after fetal
  organogenesis.

45
References

• Agabegi SS, Agabegi ED. Step-Up to Medicine, 3rd
  ed. 2013. Lippincott Williams Wilkins.
  Philadelphia, PA.
• DeGroot, LJ. Diagnosis and Treatment of Graves
  Disease. Feb 2012. http//www.thyroidmanager.org/c
  hapter/diagnosis-and-treatment-of-graves-disease/
• Sabatine MS. Pocket medicine, 4th ed. 2011.
  Lippincott Williams Wilkins. Philadelphia, PA.
• Trevor AJ, Katzung BG, Kruidering-Hall M, et al.
  Katzung Trevers Pharmacology Examination
  Board Review, 10th ed. 2013. McGraw-Hill. New
  York, NY.
• Weiner C, Fauci AS, Braunwald E, et al.
  Harrisons Principles of Internal Medicine
  Self-Assessment Board Review, 17th ed 18th
  ed. 2008, 2012. Lippincott Williams Wilkins.
  Philadelphia, PA.
• Special thanks to Dr. Sood for the inspiration!