MCQ Thyroid - Goiter, Graves disease

Diffuse goiter - it affects >5%Q of the population.

If more than half of thyroid tissue is below the opening of thoracic cageQ.• Usually arises from lower pole of a nodular goiterQ.

• Arise from accessory (ectopic) Q thyroid tissue located in the chest
• Supplied by intrathoracic blood vesselsQ

• 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

• 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

• I132 - 2.3 hoursQ
• I123 - 13 hoursQ
• I131 - 8 daysQ

• 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.

• Antithyroid drug of choice for thyroid stormQ
• Reduces hormone synthesis as well as peripheral conversion of T4 to T3Q

• Most difficult to control in the first trimesterQ
• Easiest to control in the third trimesteQ

Fetal aplasia cutisQ.

• • Aortic regurgitationQ
• • ThyrotoxicosisQ

Iodine induced hypothyroidismQ

Iodine induced hyperthyroidismQ

• 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

It is a ToxicAdenoma or hyperthyroidism from a single hyperfunctioning noduleQ

Stimulatory autoantibodies to TSH-RQ.

• Female - amenorrhea, decreased fertility and increased incidence of miscarriageQ
• Children - rapid growth with early bone maturationQ
• Old patients - CVS complications (AF and CHF)Q

• • 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).

• Acute - HemorrhageQ (brain metastasis) • Cerebral edemaQ (brain metastasis) • Vocal cord paralysisQ • Nausea and vomitingQ • Bone marrow suppressionQ
• Long term – bone marrow suppression, leukemia, infertility

• 1. Small, nontoxic goiters <40 gmsQ
• 2. Mildly elevated thyroid hormone levelsQ
• 3. Rapid decrease in gland size with antithyroid medicationsQ

• 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

Continued up to the day of surgeryQ.

7-10 days preoperatively (three drops twice daily) Q

Inhibit release of thyroid hormoneQ

• • Patients with coexistent thyroid cancerQ
• • Who refuse RAI therapyQ • Have severe ophthalmopathy Q
• • Life-threatening reactions to antithyroid medicationsQ (vasculitis, agranulocytosis, or liver failure

• 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.

Parathyroids usually can be identified within 1 cm of the crossing of the inferior thyroid artery and the RLN.

2-5 days after operationQ - circumoral and fingertip numbness and tingling tetany, carpopedal spasm and laryngeal stridor

• Asymptomatic with calcium level >8 mg/dl: No treatmentQ


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

• Severe Symptoms: IV calciumQ