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18 Cards in this Set
- Front
- Back
Thyroid nodule evaluation to cancer diagnosis (if applicable)
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Nodule found - thyroid labs drawn - thyroid imaging (US, nuclear medicine) - may biopsy - dx cancer - perform surgery, may need additional treatment
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Thyroid Cancer Types
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Papillary Carcinoma - well differentiated - 80%
Follicular Carcinoma - well differentiated - 10% Medullary Carcinoma - 5% Anaplastic Carcinoma - 2% Papillary is pretty benign but most malignant cancer anywhere in body is anaplastic thyroid cancer |
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Thyroid Nodules prevalence
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Majority of thyroid cancers present as nodules
5% of adults have palpable nodules and over half have nodules detectable by US, malignancy rate is 5%, rarely symptomatic |
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Worrisome clinical characteristics of a nodule
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Prior head and neck irradiation
Family history of MEN2 or Medullary Thyroid Cancer Age <20 or >70, Male (not factored in staging) Growing Firm/hard or fixed nodule Cervical adenopathy Dysphonia, dysphagia, cough |
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Thyroid Ultrasound Indications, Use, When is it not indicated
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Use: Best initial evaluation, tells nodule types and lymphadenopathy, can help show things that may predict malignancy (microcalcifications, etc)
Indications: Any palpable nodule, incidentally discovered nodule (ie neck x-ray or CT) Not Indicated: medical thyroid disease (hypo or hyperthyroidism) if gland does not have a palpable nodule; If hyperthryoid and hot nodule or have toxic multinodular goiter may do but not hypothyroidism. ONLY time can use as a screening test is high genetic risk or radiation exposure |
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What is main thing gained from FNA and US
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FNA developed and reduced number of surgeries needed and increased surgical yield of cancer
Thyroid US can help select patients for biopsy to increase FNA yield |
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Who needs FNA, ATA guidelines for who needs a biopsy
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Not based just on size of nodules (equal malignancy chance), MUST be larger than 5mm
Can be difficult to reach if have large neck or large goiter DO NOT use size cutoff as standard b/c not reliable ATA guidelines a) Over 5mm b) Suspicious US features OR high risk history c) ANY with lymphadenopahty d) NEVER purely cystic Others based on size but NEVER just use size |
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Workup of a Thyroid Nodule, Biopsy outcomes
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1) H&P, find out if any high risk factors (radiation, family history of thyroid cancer)
2) Check TSH (first test before any imaging). a) If TSH is low then nodule islikely overactive and most likely benign. Iodine scan positive (hyperfunctioning) means likely just hyperthyroidism so treat for that If it doesn't light up on iodine scan (non functional) want to workup with US for possibility of cancer b) TSH is normal or high, workup for possibility of cancer 3) Suspicion of cancer (nonfunctional TSH low OR normal or high TSH) - Do US to see if there is an actual nodule 4) If nodule biopsy and there are 5 outcomes a) Benign - may still monitor over time b) Non-diagnostic - repeat and if still nondiagnostic follow or consider surgery c) Malignancy - need to remove thyroid, look at lymph nodes around d) Suspicious - will remove thyroid but might be benign, can monitor if older pt or comorbid conditions e) Intermediate - Pathologist cannot determine, recommend taking out if younger b/c 1/3 of these are cancerous. I-123 scan if warm makes you think its probably OK and can just watch |
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Epidemiology of Thyroid Cancer, incidence changes, why
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1% of all cancer deaths, INCREASING incidence
Because: a) Imaging tech is driving "epidemic" of nodules being seen, majority are "incidentalomas" rather than palpable nodules ALL of the increase is from papillary carcinoma (lowest cancer risk), but the other types haven't changed at all. Biggest rise in 0-1cm tiny nodules = ASYMPTOMATIC Also mortality remained stable, so "increased diagnostic scrutiny" may be cause. |
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Staging in thyroid cancer key parts
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Prognosis worse if older than 45, If under 45 highest stage is Stage II even if have metastasis
Stages raised by Tumor size, number of lymph nodes, and metastatic disease |
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Disease Free Survival of Thyroid Cancers
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GOOD, 80% if Stage I are disease free 25 years, 97% have cancer specific survival (don't die of the disease)
As stage increases, it falls off BUT even in older pts have over 80% survival so need to balance treatment to not cause new problems |
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Risk Factors for Recurrence, Death
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Same
Tumor size, multiple tumors, metastasis, staging |
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Use of Radioactive Iodine
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Mainstay of thyroid cancer treatment after surgery, major component of thyroid hormone
Kills remaining thyroid tissue, lower risk for recurrence and death NOT conclusive though, may not decrease recurrence or mortality so may be reconsidered |
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RAI current recommendations
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T1 - smaller, low stage tumors, iodine does not decrease risk of death or recurrence so don't give it
T2 - not clear, patient can guide, may have some benefit but there are side effects T3 - Definitely recommend iodine |
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Current Conclusions for Thyroid Nodules
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Stage I cancers are low risk, with very low rates of cause-specific mortality
Treat with total or near-total thyroidectomy Remnant ablation has little effect on small tumors Node positivity and distant metastasis increase risk for recurrence and mortality RAI limited benefit in small tumors (T1) |
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Problems with over diagnosing, Is there a benefit
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Needless surgeries
Requires lifelong thyroid hormone replacement Requires lifelong followup Benefit Very sensitive screening test (US) for common indolent disease (1/3 cadavers has thyroid cancer but clinical disease is only 1% of all cancers and 0.5% of deaths) Cannot just go off nodule size, imaging properties more important for which ones actually warrant further workup Similar to prostate cancer |
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Molecular marker suggesting aggressive disease
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BRAF mutations - part of protein kinase pathway leading extracellular signal regulated kinase (ERK) regulating cell survival, proliferation, differentiation
Also seen in melanomas, could be potential therapeutic target as well as diagnostic tool BRAF mutation seen in 50% of thyroid cancers, more likely to be invasive and aggressive and recurrent. MAY BE helpful |
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Treatment for Micropapillary Thyroid Cancer
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Surgery is Standard of care, BUT debate over total vs near-total thyroidectomy
Current is central compartment dissection but raises risk of hypoparathyroidism |