Thyroid Pathology Flashcards
What is the term for normal function of the thyroid?
Euthyroid
What is the most common cause of thyrotoxicosis?
Hyperthyroidism
What is the most common cause of hyperthyroidism?
Graves Disease
What are the symptoms of Graves disease? (4)
- Hyperthyroidism
- Goiter
- Ophthalmopathy (eye protrusion)
- Graves dermopathy (pretibial myxedema)
What disease is associated with the “thyroid storm”?
Graves disease
What pathology is seen with thyroid inferno?
Graves disease - due to hypervascularity
What measurement is considered diffuse enlargement of the isthmus?
> 1cm
What is the most common presentation of thyroiditis?
Hypothyroidism
Acute presentation of thyroiditis?
- Low grade fever
- Sore neck
In what population is acute suppurative thyroiditis seen in?
Peds
What is thought to be the cause of subacute thyroiditis?
A viral infection
Patient symptoms of subacute thyroiditis?
- Neck pain
- Radiating pain down jaw, throat, and ears
In how many weeks does subacute thyroiditis usually resolve?
2-6 weeks and thyroid function is back to normal in 6-8 weeks
What is the vascularity of acute and subacute thyroiditis?
Normal or lessened
What is the most common thyroid function disorder?
Primary Hypothyroidism
What causes secondary hypothyroidism?
Malfunction of either the hypothalamus or anterior pituitary
What is the most common cause of hypothyroidism?
- In iodine sufficient countries = Hashimoto’s hypothyroidism (autoimmune disorder)
- In developing countries = iodine insufficiency
What is the peak incidence of primary hypothyroidism?
45-65
What is hashimoto’s thyroiditis associated with? (5)
- Genetics
- Smoking
- High iodine intake
- Selenium deficiency
- Chronic hep C
Symptoms for hypothyroidism?
- Cold intolerance
- Weight gain
- Dry skin
- Constipation
- Decreased sweating
- Hoarseness
Sonographic features of Hashimoto’s Thyroiditis?
- Early stages = hypoechoic, coarse echotexture, diffuse enlargement
- Later = Fibrosis and lobulations
- Even later = heterogenous, small hypoechoic nodules, decreased size
Goiter symptoms? (4)
- Dysphagia
- Hoarseness
- Inspiratory stridor
- Venous congestion
Why may a non-toxic goiter occur?
Hypothyroidism due to insufficient iodine in food, water, and soil
In a non-toxic goiter, what are the levels of iodine, T3/4, and TSH?
Iodine = decreased
T3/4 = decreased
TSH = increased to try and compensate
T or F? Toxic goiters are usually multinodular?
TRUE
What can toxic goiters induce?
Hyperthyroidism, graves disease, thyrotoxicosis
What does it mean when a multinodular goiter is “plunging”?
It means that the tissue is extending below the clavicle and into thoracic cavity
SF of multinodular goiters?
- Multinodular, lobulated
- Heterogenous
- Possible calcifications
- Can be asymmetrically enlarged
What thyroid pathology can either be toxic or non-toxic?
Multinodular goiters
What is a common presentation of thyroid disease in pregnancy?
Enlarged thyroid due to hormonal changes
What is the most common thyroid condition after abortion, miscarriage, or delivery?
PPT (postpartum thyroiditis)
What is the classic presentation of PPT?
Thyrotoxicosis followed by hyPOthyroidism
SF of PPT?
- Hypoechoic
- Diffuse enlargement
What causes the majority of NODULAR disease?
Hyperplasia of the thyroid due to iodine deficiency or under-utilization
SF of thyroid hyperplasia?
- Most commonly isoechoic but can become more echogenic as it increases in size
- Peripheral vascularity around nodule
- Cystic degeneration
What are thyroid cysts usually due to ?
Hemorrhage or degeneration of thyroid nodules
What is a treatment of thyroid cyst (if symptomatic) ?
Percutaneous ethanol injection if benign and surgical removal if malignant
What do simple thyroid cysts contain within?
A large amount of colloid
T or F? Colloid cysts are not very common
FALSE: they are very common
What pathology contains small echogenic foci with comet-tail artifact?
Colloid cysts containing colloid crystals
Hemorrhagic thyroid cysts contain what?
Blood and debris
What pathology is “layered debris” a characteristic of?
Hemorrhagic cyst
Most common reasons (2) why thyroid nodules occur?
- Increased age
- Decreased iodine intake
Are hot or cold nodules more common?
COLD
What determines a hot nodule?
When there is a dense collection - more iodine is trapped
Is a hot nodule non-functioning or hyperfunctioning?
Hyperfunctioning
What determines a cold nodule?
Does not trap iodine meaning it is non-functioning
Do hot or cold nodules imply it’s benign?
HOT
What are thyroid adenomas derived from?
Follicular cells
Are most adenomas non-functioning or hyperfunctioning?
NON-functioning; although a small amount may produce thyroid hormone leading to hyperthyroidism (toxic adenoma)
Most common SF of adenoma?
- Solid/solitary
- Well-circumscribed
- Oval shaped
- Rim calcifications
- “spoke and wheel” vascularity
What is the most common thyroid cancer?
Papillary
What is the 2nd most common thyroid cancer?
Follicular
What are the traditional SF features of thyroid malignancy?
Hypoechoic and solid
What is one of the most suspicious features of malignancy?
Microcalcifications <2mm
What 3 factors may raise suspicion of malignancy?
- When nodule is taller than it is wide
- When it is VERY hypoechoic
- Tumor invasion or lymph node METS
What SF are associated with high thyroid cancer risk (9)?
- Hypoechoic
- Solid
- Microcalcifications (<2mm)
- Central vascularity
- No halo
- Ill-defined margins
- Taller than it is wide
- Local invasion and lymphadenopathy
- Increased tissue stiffness
What SF are associated with low thyroid cancer risk (6)?
- Iso- or hypoechoic
- Can be cystic or solid
- Large, coarse calcifications
- Peripheral vascularity or none
- Egg-shell calcifications
- Insipissated colloid; comet-tail artifact
What is the mode of spreading of papillary cancer vs. follicular cancer?
Papillary cancer spreads via lymphatics
Follicular cancer spreads via blood stream
SF of papillary cancer?
- Hypoechoic
- Microcalcifications
- Hypervascular
- Punctate microcalcifications can appear in lymph nodes if METS is present
Where is METS common with follicular carcinoma? (3)
- Lungs
- Liver
- Bones
What may be a cause of increased incidence of follicular cancer?
Areas of dietary iodine deficiency
T or F? Follicular adenomas and carcinomas CANNOT be distinguished on sonography or FNA?
TRUE
SF of follicular carcinoma?
- Ill-defined margins
- Hypervascular
- Thickened halo
What is the least aggressive and has the best prognosis for thyroid cancers?
Papillary Carcinoma
Where is medullary carcinoma derived from?
Parafollicular cells (c-cells)
What is a lab marker that we look for with medullary carcinoma?
Increased calcitonin because parafollicular cells secrete calcitonin
What syndrome is medullary carcinoma associated with?
MEN = multiple endocrine neoplasia
T or F? Medullary carcinoma responds to radiation and chemo?
FALSE - this tumour is quite aggressive
CP of medullary carcinoma?
- Mass in the neck causing hoarseness or dysphagia
- Due to endocrine secretion, patients may suffer from carcinoid syndrome and Cushing syndrome
Local invasion & metastasis to cervical lymph nodes is more often in patients with?
Medullary cancer
What thyroid cancer invades nearby vasculature and muscles, widespread mets?
Anaplastic thyroid carcinoma
SF of anaplastic carcinoma?
- Large
- Solid
- Hypoechoic mass
- Invading blood vessels
- Possible invasion of other nearby structures
What do Hurthle-cell carcinomas produce?
Thyroglobulin protein
What thyroid pathology is most commonly seen in males?
Hurthle-cell carcinoma
What do patients usually have a history of in thyroid lymphoma?
Hashimoto’s disease
Thyroid lymphoma symptoms?
Obstructing airway symptoms:
- Dyspnea
- Dysphagia
SF of thyroid lymphoma?
- Large
- Hypoechoic mass
- Solid
- Cystic necrosis
Via what method is thyroid METS usually spread by?
Through blood rather than lymphatics
What are the most common organs of thyroid METS (4)?
- Breast
- Lung
- Melanoma
- RCC
SF of lymphadenopathy?
- Round
- Hypoechoic
- Loss of fatty hilum
- Cystic necrosis
- Increasing size
- Mixed vascularity
- METS from papillary cancer - node calcifications and HYPERECHOIC nodes
What are two other names for subacute thyroiditis?
De quervian disease
Granulomatous thyroiditis
What causes the majority of nodular disease?
Hyperplasia
What abnormality is percutaneous ethanol injection used for?
Benign thyroid cysts when symptomatic