(step2CK) Thyroid 문제 감별 문제 운영자 / 2005-09-16 12:04:52
tender thyroid gland 그리고 며칠전의 URI Hx. 원인은?
(subacute thyroiditis 의 원인을 묻는 문제) viral inection.
Case Presentation (Questions 2a-2c):
A 45 year-old white female presents to your clinic with neck pain worsened by coughing &swallowing. She reports fatigue, nervousness, myalgias, and fevers to 103 Exam reveals a moderately enlarged thyroid, exquisitely tender to palpation.
2a.What is the most likely diagnosis?
De Quervain subacute thyroiditis (SAT). This is the second most common cause of thyrotoxicosis (~20%) behind Graves Disease (50-60%). Although usually not necessary, the diagnosis can be confirmed by 24-hr RAIU testing, which will show low uptake.
2b.What lab abnormalities could we expect to find in this patient?
Abnormally high free T4, total T3.
Abnormally low TSH.
Anemia; leukocytosis; high alk phos & ferritin; elevated ESR (often exceeding 100).
2c.What is the treatment of choice?
NSAIDS (ie. Naproxen 500 bid or Ibuprofen 800 tid). For severe disease, glucocorticoids may be used (ie. prednisone 30mg-60mg per day for one week, then tapered over 2weeks). Steroids are highly effective; if pain and tenderness do not disappear within 72hours of initiating therapy, question the diagnosis. Symptomatic therapy with propranolol is often prescribed.
Case Presentation (Questions 5a-5c)
A 28 year-old female presents to your clinic with complaints of heat intolerance, palpitations, anxiety, and oligomenorrhea, Exam reveals mild systolic hypertension, tachycardia, exophthalmos, lid lag, non-pitting leg edema, and a diffusely enlarged firm painless thyroid gland.
5a. What is the most likely diagnosis?
Graves disease. Ophthalmic findings (proptosis, chemosis, periorbital edema) and non-pitting edema are classically associated with Graves.
5b. What lab abnormalities could we expect to find in this patient?
Abnormally low TSH.
Abnormally high free T4 and T3.
Abnormally high anti-thyroperoxidease (anti-TPO) antibody; this level is also high with post-partum subacute thyrotoxicosis but is low in toxic multinodular goiter & toxic adenoma.
Abnormally high thyroid-stimulating immunoglobulin (TSI) G, a TSH receptor agonist.Elevated alk phos, hypercalcemia, anemia & thrombocytopenia.
5c What are treatment options for this disease?
For symptom relief, beta-blocker therapy. If contraindicated, such as in asthmatics, calcium channel blockers can be used.
For reduction in T4 & T3 synthesis, methimazole & propylthiouracil are used. These are often used until definitive therapy with radioactive iodine can be performed. They also may be used in Graves disease, since some patients go into remission after treatment for 12-18 months.
While methimazole is longer-acting (given qday or bid instead of tid or qid), PTU is often chosen in severe thyrotoxicosis because of its additional benefit of inhibition of T4 to T3 conversion. (T3 is 20-100 times more potent than T4.) Iodine therapy also blocks T4 to T3 conversion & release of thyroid hormone from the gland.
Iodine therapy is reserved for severe thyrotoxicosis because its use prevents definitive
therapy of Graves with radioactive iodine for many weeks.
Radioactive iodine therapy is the most common treatment of hyperthyroidism. It is administered orally as a single dose, causing fibrosis and destruction of the thyroid over weeks to months. Hypothyroidism is not an unexpected result of this therapy.
Surgical therapy is reserved for severe cases in children & patients intolerant of traditional therapies.
Case Presentation (Questions 6a-6c)
A 65 year-old female presents to your clinic with unexplained weight loss and depression. Exam reveals a nontender goiter which has been present for many years, but now there are multiple irregular nodules palpable. Lab reveals a depressed TSH and borderline high T3 & T4.
6a. What is the most likely diagnosis?
Toxic multinodular goiter (15-20%). Plummer disease occurs most commonly in the elderly and develops slowly over time. Symptoms of thyrotoxicosis are mild & thyroid hormones are only slightly elevated.
6b. What are the expected results from RAIU and thyroid scintigraphy?
RAIU is high and thyroid scintigraphy shows the characteristic pattern of increased &
decreased activity.
6c. What are the treatment choices for this disease?
Radioactive iodine therapy is the treatment of choice. Thioamides (PTU, methimazole)
are often given 2-8 weeks before radioactive iodine ablation to avoid precipiration of thyroid storm. Beta-blockers relieve sympathetic symptoms. Surgery is usually reserved for young individuals with large nodules or obstructive symptoms.
