MCQ Thyroid - Goiter, Graves disease

  1. What is Endemic Goiter?
    Diffuse goiter - it affects >5%Q of the population.
  2. What is intrathoracic goiter?
    If more than half of thyroid tissue is below the opening of thoracic cageQ.• Usually arises from lower pole of a nodular goiterQ.
  3. What is primary intrathoracic goiter?
    • Arise from accessory (ectopic) Q thyroid tissue located in the chest
    • Supplied by intrathoracic blood vesselsQ
  4. What is secondary intrathoracic goiter?
    • Constitute majorityQ of mediastinal goiters
    • Arise from downward extension of cervical thyroid tissueQ along the fascial planes of the neck and
    • Derive their blood supply from the superior and inferior thyroid arteriesQ
  5. Surgical approach for intrathoracic goiter?
    • intrathoracic goiters can be removed via a cervical incisionQ.
    • Indications of Median Sternotomy are –
    • 1. Invasive thyroid cancersQ
    • 2. Had previous thyroid operations and may have developed parasitic mediastinal vesselsQ
    • 3. Primary mediastinal goiters with no thyroid tissue in the neckQ
  6. T1/2 of various iodine Isotopes?
    • I132 - 2.3 hoursQ
    • I123 - 13 hoursQ
    • I131 - 8 daysQ
  7. Role of propranolol in thyroid storm?
    • Most valuable measure in thyroid stormQ.
    • Most of the symptoms are because of adrenergic over activity due to increased tissue sensitivity to catecholamines in hyperthyroidism.
    • This increased sensitivity is due to increased number of beta receptorsQ.
  8. MOA os Propylthiouracil in thyroid storm?
    • Antithyroid drug of choice for thyroid stormQ
    • Reduces hormone synthesis as well as peripheral conversion of T4 to T3Q
  9. Ease of control of Hyperthyroidism in pregnancy?
    • Most difficult to control in the first trimesterQ
    • Easiest to control in the third trimesteQ
  10. Metimazole teratogenicity?
    Fetal aplasia cutisQ.
  11. Causes of Dancing Carotids?
    • • Aortic regurgitationQ
    • • ThyrotoxicosisQ
  12. What is Wolff-Chaikoff effect?
    Iodine induced hypothyroidismQ
  13. What is Jod-Basedow’s effect?
    Iodine induced hyperthyroidismQ
  14. Limitations of beta-blockers in thyrotoxicosis?
    • Do not significantly affect the thyroid statusQ, it reduces to some extent the conversion of T4 to T3.
    • Do not correctQ the underlying metabolic abnormalities (i.e. does not affectt the oxygen consumption) Q
  15. What is Plummer’s disease?
    It is a ToxicAdenoma or hyperthyroidism from a single hyperfunctioning noduleQ
  16. Graves disease etiology?
    Stimulatory autoantibodies to TSH-RQ.
  17. Clinical features of graves disease?
    • Female - amenorrhea, decreased fertility and increased incidence of miscarriageQ
    • Children - rapid growth with early bone maturationQ
    • Old patients - CVS complications (AF and CHF)Q
  18. Signs in Grave’s disease?
    • • Overlying bruit or thrill at upper poleQ due to increased vascularity
    • • Loud venous humQ in supraclavicular space
    • • Ophthalmopathy (orbital proptosis) occurs in 50%, dermopathy in 1-2%.Q
    • • Dermopathy is characterized by deposition of glycosaminoglycans leading to thickened skin in pretibial regionand dorsum of footQ (pretibial myxedema).
  19. Complications of Radioactive iodine?
    • Acute - HemorrhageQ (brain metastasis) • Cerebral edemaQ (brain metastasis) • Vocal cord paralysisQ • Nausea and vomitingQ • Bone marrow suppressionQ
    • Long term – bone marrow suppression, leukemia, infertility
  20. Treatment for curative intent is reserved in Graves disease?
    • 1. Small, nontoxic goiters <40 gmsQ
    • 2. Mildly elevated thyroid hormone levelsQ
    • 3. Rapid decrease in gland size with antithyroid medicationsQ
  21. Disadvantages of radioactive iodine?
    • Progression of Grave’s ophthalmopathyQ
    • Small increased risk of nodular goiter, thyroid cancer and hypoparathyroidismQ
    • Unexplained increase in overall and cardiovascular mortalityQ
    • Higher initial dose of 131I: Earlier onset and higher incidence of hypothyroidism
  22. When are antithyroid drugs stopped in Graves disease before surgery?
    Continued up to the day of surgeryQ.
  23. Dose of Lugol’s iodine?
    7-10 days preoperatively (three drops twice daily) Q
  24. Mode of action of Lugol iodine?
    Inhibit release of thyroid hormoneQ
  25. Indications of Total or near-total thyroidectomy in Graves disease?
    • • Patients with coexistent thyroid cancerQ
    • • Who refuse RAI therapyQ • Have severe ophthalmopathy Q
    • • Life-threatening reactions to antithyroid medicationsQ (vasculitis, agranulocytosis, or liver failure
  26. Where should the vessels be ligated in thyroidectomy?
    • Both superior and inferior thyroid vessels should be ligated close to the thyroid.
    • Superiorly, to avoid injury to the external branch of the superior laryngeal nerve.
    • Inferiorly, to minimize devascularization of the parathyroids (extracapsular dissection) or injury to the RLN.
  27. Localization of parathyroid intraoperatively?
    Parathyroids usually can be identified within 1 cm of the crossing of the inferior thyroid artery and the RLN.
  28. When do features of hypocalcemia develop after parathyroid injury in thyroidectomy?
    2-5 days after operationQ - circumoral and fingertip numbness and tingling tetany, carpopedal spasm and laryngeal stridor
  29. Management of post-operative hypocalcemia?
    • Asymptomatic with calcium level >8 mg/dl: No treatmentQ

    Mild symptoms or calcium level <8 mg/dl: Oral calciumQ

    • Severe Symptoms: IV calciumQ
Card Set
MCQ Thyroid - Goiter, Graves disease