| What is the epidemiology of thyroid nodules? | They are very common (5-10% have a palpable nodule), 16-68% are discovered incidentally by US, it ocurs in 50% of women in age of 50, and affects women more than men, 7-15% are malignant (papillary thyroid cancer is the most common type), 63000 cases/year |
| What are the risk factors for cancers in nodules? | Age <20 or >70, male sex, associated dysphagia or dysphonia, history of neck irradiation, prior history of thyroid carcinoma, firm hard and immobile nodule, presence of cervical lymphadenopathy, family history |
| What are factors that suggest a benign tumor? | Family history of autoimmune thyroiditis/ benign nodule, presence of hormonal dysfunction (hypo or hyperthyroidism), pain or tenderness of nodule, soft smooth and mobile nodule |
| What are the lab tests done for thyroid nodules? | Most important is TSH level (should be normal, if it is high this suggests cancer), sometimes we do T3 and T4 levels |
| What is an autonomous nodule? | AKA Hot nodule, this nodule supresses TSH levels, could be subclinical (no change in fT4) or overt (supressed thyroid hormones), no need for FNA, we treat with radioactive iodine I-131/ surgery |
| What are the imaging techniques used for thyroid evaluation? | Thyroid scintigraphy, US |
| What is the indication of thyroid scintigraphy for thyroid nodules? | It is done with radioactive iodine/ technicium (more used in lebanon)
Done only for pt with suppressed TSH (hyperthyroid), it distinguished hot, cold and warm nodules.
Hot indicates autonomous, warm indicates normal thyroid and cold indicates hypofunctional thyroid 5-8% of them are malignant while hot ones are usually benign. so we do FNA for cold nodules |
| What is the indication for an US for thyroid nodules? | It is the best modality for dx, highly sensitive for size and number of nodules, but cannot tell us about tertagenicity of the nodule, so we can use US with doppler to reveal vascularization and see if malignant |
| What are the characteristics that tell if a thyroid nodule is malignant or not? | Size, vascularity, presence of halo or not, presence of microcalcification or not, diameter (taller than wide?), echogenicity, margin (regular or irreegular), component (solid or cystic), Rim calcification (eggshell vs. interrupted), extrathyroidal extension |
| What is the indication of echogenicity regarding the malignancy of a thyroid nodule? | We see it on US, if the nodule is hypoechoic (mild moderate or severe) then it suggests cancer
hyperechoic nodules are usually benign and isoechoic ones are similar to the surrounding. |
| What is the indication of the shape regarding malignancy of a thyroid nodule? | If the nodule is harmonious with thyroid (same direction) this suggests a benign nodule, if disharmonious (taller than wide) it suggests malignancy
Also effaced capsule suggests malignancy |
| What is the indication of border regarding the malignancy of a thyroid nodule? | Irregular border --> more malignancy |
| What is the indication of microcalcifications regarding the malignancy of a thyroid nodule? | White spots increase the risk for cancer, but macrocalcifications are not malignant. |
| What is the indication of vasculature regarding malignancy of a thyroid nodule? | if there is peripheral vasculature --> benign, if intranodular--> malignant. |
| What is the indication of rim calcification regarding mailgnancy of a thyroid nodule? | smooth eggshell rim indicates benign, interrupted calcium rim indicates malignancy
If we have a black rim/ halo --> suggests benign |
| What is the indication of extra-thyroid extension regarding malignancy of a thyroid nodule? | if it goes out of thyroid --> malignant |
| What is the indication of component of thyroid nodule on its malignancy? | Cyst form (benign if under 2cm), partially cystic/solid then moderate risk (1.5cm), if pure cystic all black and clear, cyst with colloid (comet shapes) then benign
Solid == malignant |
| What is the indication of PET scan thyroid nodule? | if + -->35% cancer |
| What is the indication of nodule size on its malignancy? | If it is enlarging quickly this indicates malignancy. |
| What are the indications for a FNA? | If highly sus nodule >=1cm we make FNA, if low sus >1.5cm we make FNA, if very low >2cm make FNA, if benign no need |
| What are the types of thyroid cancer? | Papillary (easiest treated) and anaplastic (bad prognosis cannot be cured) |
