Thyroid Pathology (Unit 2B) + TIRADS (Unit 4) Flashcards
What are examples of diffuse pathology of the thyroid gland? (3)
Inflammatory/infectious
Thyroditis
Autoimmune
What are examples over focal pathology of the thyroid gland? (6)
Nodules (single/multiple)
Hyperplasia
Adenoma
Carcinoma
Lymphoma
Mets
What is Euthyroid?
Normal functioning thyroid gland
What is Thyrotoxicosis/Hyperthyroidism caused by?
Elevated levels of free T3 and T4 = causes a hypermetabolic state
What is the difference between Primary Hyperthyroidism and Secondary Hypterthyrodism?
Primary - excess thyroid hormone is synthesized and secretes by the thyroid gland
Secondary - caused by outside source
What is the most common cause of hyperthyroidism?
Graves Disease (autoimmune disease)
What are the symptoms of hyperthyroidism/thyrotoxicosis?
- Hyperthyroidism
- Diffuse thyroid enlargement (goiter)
- Ophthalmopathy (protrusion of the eyes)
- Graves dermopathy (pretibial myxedema)
What are the clinical manifestations of Hyperthyroidism?
- Weight Loss (unintentional, severe)
- Excessive sweating
- Heat intolerance
- Ophthalmopathy (bulging eyes)
- Enlarged thyroid (goiter)
- Tachycardia at rest
- Mood changes
- Dyspnea
- Nervousness
- Hand Tremors/Muscular weakness
- Menstrual irregularities (Oligomenorrhea or
amenorrhea)
What is a Thyroid Storm?
Increased HR, BP, and body temperature all to extreme degrees
What are the symptoms of children who have hyperthyroidism?
- accelerated growth spurts and advanced bone age
- emotional lability
- hyperactivity
- difficulty concentrating
- occasionally failure to thrive
What is the sonographic appearance of Hyperthyroidism/Grave’s Disease?
- normal or enlarged
- heterogenous (when enlarged)
- hypervascularity
- peak velocities exceeding 70 cm/sec)
- diffuse enlargement of isthmus >1cm
What are 5 symptoms of Thyroiditis?
- Dysphagia
- Pain radiating to ear
- Thyroid gland visibly enlarged on one side
- Tender pretracheal lymph nodes
- Thyroid gland = tender, palpable
What is the presentation for acute Thyroiditis?
Low grade fever & sore neck
What is subacute thyroiditis also called?
De Quervain Disease or Granulomatous Thyroiditis
What is the clinical presentation of Subacute Thyroiditis?
- Hx of recent viral infection
- Neck pain which can radiate to upper jaw, throat or ears. Associated with other
symptoms of inflammation (fever, tenderness, fatigue, etc) - Unilateral or bilateral enlargement of gland
- Usually temporary, resolves in 2-6 weeks with spontaneous recovery of thyroid function
in 6-8 weeks - Good recovery, may have some residual fibrosis
What does Subacute Thyroiditis look like on US?
- Enlargement
- Hypoechoic
- Normal or decreased vascularity
- Nodularity
What is the most common thyroid function disorder?
Hypothyroidism
What is secondary (central) hypothyroidism?
- Pituitary or hypothalamus failing to stimulate normal thyroid function
What is the most common cause of primary hypothyroidism?
chronic autoimmune thyroiditis (aka Hashimoto thyroiditis)
Describe the clinical relevance of Primary Hypothyroidism.
- Peak incidence: 45 and 65 years of age
- Females > Males
- Associated with genetic predisposition, high iodine intake, selenium deficiency,
smoking, and chronic hepatitis C - Associated with other autoimmune disease (Sjögren syndrome, lupus,
rheumatoid arthritis) - Diagnosed clinically with blood work
What are the key clinical manifestations of hypothyroidism?
- weakness/fatigue
- dry skin
- cold intolerance
- hoarseness
- weight gain
- constipation
- menstrual irregularities
- decreased sweating
Hasimoto’s Thyroiditis can appear like which other Thyroid issue in US?
Graves disease
- abnormal echotexture
- often hypervascular
Describe the appearance of the 3 stages of Hashimoto’s Thyroiditis.
Early: increased size, coarse echotexture, hypo to normal echogenicity
Late: fibrotic strands cause lobulations
Even later: Multinodular, heterogenous, with multiple small hypoechoic nodules throughout, can appear ill defined and atrophic
What is a common measurement of the isthmus to suggest a goiter?
Greater than 1cm
What are the symptoms associated with goiters? DIVH
- Dysphagia
- Inspiratory stridor
- Venous congestion
- Hoarseness
An endemic non toxic goiter is due to an iodine deficiency in food/water/soil in a given area - what happens to the thyroid?
Hypothyroid (decrease in iodine, decrease in T3/4, INCREASE in TSH)
Toxic goiters are typically what and induce what?
Multinodular, can induce hyperthyroidism, thyrotoxicosis, graves disease
Multi-lobulated goiters are enlarged in which way? Symmetrical or asymmetrical?
Asymmetrical
What is a plunging goiter?
When one or both lobes extend below the clavicle or sternum
What is the sonographic appearance of a multinodular goiters?
- Heterogeneous
- Lobulated, multinodular
- Possible calcifications
In multinodular goiters what is it important to look for?
Important to look for other discrete nodules within the goiter as neoplasms and cancers can exist within a goiter
What commonly happens to the thyroid and pregnancy?
Enlarges due to reduction in plasma idoine
What is the most common thyroid condition after abortion/miscarriage/delivery?
Postpartum Thyroiditis (PPT)
What is the clinical presentation and sonographic appearance of postpartum thyroiditis?
- Classic presentation: thyrotoxicosis followed by hypothyroidism
- Sono appearance: ↓ echogenicity, diffuse enlargement of thyroid (non specific)
What causes the majority of nodular diseases in the thyroid?
Hyperplasia
A nontoxic goiter is typically: euthyroid, hyperthyroid, hypothyroid?
Euthyroid
Hyperplasia in thyroids occur due to?
Iodine deficiency or under utilization
What is the most common sonographic appearance of hyplerplasia?
Isoechoic
Can also have: peripheral halo, cystic degeneration, perinodular vascularity
What is the treatment for benign thyroid cysts?
Percutaneous ethanol injection
What are the 2 types of thyroid cysts?
Simple, complex
What are the 2 types of complex cysts?
Colloid, hemorrhagic
What does a simple thyroid cyst look like on ultrasound?
- Typically circular/oval
- Distinct margins
- No internal echoes
- Posterior enhancement
What does a colloid thyroid cyst look like on ultrasound?
- Very common
- Irregularly enlarged follicles containing abundant
colloid - Can have calcifications
- May have multiple echogenic foci (colloid crystals)
with comet tail artifact (not to be confused with
microcalcifications)
What does a hemorrhagic thyroid cyst look like on ultrasound?
- May contain blood and debris
- May have complex internal echoes, septa, debris
(layered debris @ dependent portion is highly
characteristic of hemorrhage)
What does a Hot Thyroid Nodule look like on a technetium-99m (Tc-99m) Nuclear Medicine
scintigraphy examination?
(hyper-functioning/autonomous). Area of dense collection of activity on nuclear
med image
Does a hot thyroid nodule on a nuc med test indicate malignancy?
No, typically benign
What does a Cold Thyroid Nodule look like on a technetium-99m (Tc-99m) Nuclear Medicine
scintigraphy examination?
(non-functioning). Area of decreased/absent activity on nuclear med image
Of hot or cold thyroid nodules on a nuc med test, which is to be more concerned with malignancy?
Cold
Most Thyroid Adenomas come from which histological subtype?
Follicular cells
The majority of Thyroid Adenomas are non functioning (cold) or functioning (hot)?
Non functioning (cold)
A toxic adenoma does what?
Produces thyroid hormone and causes hyperthyroidism
How large can a thyroid adenoma be?
> 2.5 - 3.0cm
What is the most common sonographic appearance for a thyroid adenoma?
Solitary, well circumscribed, oval/circular
What is the colour doppler appearance for a thyroid adenoma look like?
Spoke & wheel
What is the most common type of thyroid cancer?
Papillary (75-85%)
What is the second most common type of thyroid cancer?
Follicular (10-20%)
What is needed to confirm a thyroid carcinoma malignancy?
FNA/biopsy
What is one of the most specific features of malignancy in a thyroid carcinoma?
Microcalcifications (<2mm)
Are thyroid carcinomas hypoechoic or hyperechoic?
hypoechoic
What is associated with INCREASED thyroid cancer risk?
HEMIIISLE
- hypoechogenicity
- entirely solid
- microcalcifications
- intrinsic hypervascularity (central part)
- incomplete or absent halo
- ill-defined margin
- shape: tall > wide
- local invasion of lymphadenopathy
- eleasticity indication of increased tissue stiffness compared to normal tissue
What is associated with LOW thyroid cancer risk?
HCLEPI
- hyperechoic or isoechoic
- cystic elements
- large, coarse calficiations (except medullary thyroid cancer)
- eggshell calcifications
- perinodular hypervascularity or avascular node
- inspissated colloid; comet-tail shadowing
What is the least aggressive and best prognosis thyroid cancer?
Papillary
How doe papillary carcinoma spread?
Via lymphatics
What is the clinical presentation of Papillary Carcinoma?
- Painless palpable lump
- Palpable nodule with enlarged cervical lymph nodes
- Enlarged cervical lymph nodes without palpable thyroid nodule
What is the most accurate way to get a diagnosis for Papillary Carcinoma?
FNA biopsy
What are the treatment options for Papillary Carcinoma?
Variable. Total or partial thyroidectomy, radical neck dissection. Usually followed by suppressive therapy
What is the sonographic appearance of Papillary Carcinoma?
HMHP
- Hypoechogenicity**
- Microcalcifications*
- Hypervascularity with disorganized vessels
- Punctate microcalcifications may appear in the affected lymph nodes if metastasis is present
How does follicular carcinoma spread?
Hematological spread
What is the clinical presentation of follicular carcinoma?
- Slow growing, painless nodule
- Mets to bone, lungs or liver is seen with this type
What is the most accurate way to get a diagnosis for Follicular Carcinoma?
Histologically
What are the treatment options for Follicular Carcinoma?
- lobectomy or thyroidectomy
- Widely invasive tumors are usually followed by radioactive iodine treatment
What type of carcinoma/adenoma CANNOT be distinguished on sonography or with FNA?
Follicular
What is the sonographic appearance of Follicular Carcinoma?
Appearances overlap with follicular adenomas
Can sometimes have features of malignancy (although rarely):
- Irregular margins
- Thick irregular halo
- Hypervascularity
Medullary Carcinoma is derived from which types of cells? And what do they secrete?
Parafollicular cells (c-cells) - secrete calcitonin
What serum increases with Medullary Caricnoma?
Serum calcitonin
What type of carcinoma is associated with MEN syndrome?
Medullary
What is the clinical presentation of Medullary Carcinoma?
Clinical Presentation:
- Mass in the neck (can cause dysphagia or hoarsenes)
- Patients often suffer a number of symptoms related to endocrine secretion (including carcinoid
syndrome (serotonin) and Cushing syndrome)
What is the sonographic appearance of Medullary Carcinoma?
Sonographic Appearances:
- Similar to papillary carcinoma (local invasion & metastasis to cervical lymph nodes is more often in
patients with medullary carcinoma)
What is an aggressive and poor prognosis carcinoma?
Anaplastic Thyroid Carcinoma
What is the clinical appearance of Anaplastic Thyroid Carcinoma?
- Rapidly enlarging neck mass with symptoms relating to the destruction of local structures (dyspnea,
dysphagia, hoarseness, cough)
What is the sonographic appearance of Anaplastic Thyroid Carcinoma?
- Large, solid, hypoechoic mass with demonstration of encasing or invading blood vessels and possible
invasion of other nearby structures - Difficult to assess due to size, ultrasound usually inadequate to assess the extent/invasion (CT or MRI is
better)
What type of Carcinoma is more popular in men?
Hurthle Cell Carcinoma
What type of cells does Hurthle Cell Carcinoma produce?
Thyroglobulin
How do you classify Hurthle Cell Carcinoma as benign or malignant?
Histology
What is the clinical presentation of Thyroid Lymphoma?
- Most arise in the setting of chronic thyroiditis (Hashimoto)
- Rapidly growing mass
- Symptoms of airway obstruction (dyspnea, dysphagia)
What is the sonographic appearance of Thyroid Lymphoma?
- Large, solid, hypoechoic mass
- Infiltration of thyroid parenchyma and even encasement of neck vessels (CCA, IJV)
- Cystic necrosis
- Doppler: nonspecific. Hypovascular or chaotic blood vessel distribution
How is thyroid mets most commonly spread?
By blood
What is the sonographic appearance of lymphadenopathy?
- Round
- Hypoechoic
- Absence of fatty hilum
- Cystic necrosis within
- Increasing size (esp on serial exams, and with mets)
- Mixed / chaotic vascularity
- Mets from PTC – calcifications in the nodes is common and lymph node appears hyperechoic
How large are macro-calcifications defined as in the thyroid with TIRADS ?
Greater than or equal to 2mm
Echogenic foci _____mm, occcasionally can have comet tail _____mm.
<2
<1
When do you not use TR descriptors for nodules?
Under 5mm
If rim calcifications obscure the nodule, what do you choose the composition to be?
Solid
If rim calcifications obscure the nodule, what do you choose the echogenicity to be?
isoechoic
If the margin cannot be determined in a thyroid nodule, how do you describe the borders in TIRADS?
ill-defined
If the echogenicity cannot be determined in a thyroid nodule, how do you describe the echogenicity in TIRADS?
isoechoic
If the composition cannot be determined in a thyroid nodule, how do you describe the composition in TIRADS?
solid
When do you stop further characterization of a nodule in TIRADS?
If it is spongiform and identified as TRI
What are the 2 biggest limitations of FNA?
- Lacks specificity for certain cancers (Follicular carcinoma, Hurthle cell carcinoma, and lymphomas)
- Inconclusive results are common, often need repeating
