7 - Pathology of the Thyroid Flashcards
What pathology of the thyroid will this cover?
- Hyperthyroidism
- Hypothyroidism
- Goiter
- Thyroid neoplasms
Give a basic overview of the types of hyperthyroid
All hyperthyroidism is too much T3 or T4
- Primary = problem with thyroid
- Secondary = problem with pituitary
- Tertiary = problem with TSH
What are the signs and symptoms of hyperthyroidism?
EMPHASIZED THIS
Hypermetabolism
- Weight loss
- Muscle atrophy
- Heat intolerance (fanning themselves)
- Increased appetite
- Patients sweat (and skin feels moist)
Enhanced epinephrine effect
- Anxiety
- Fine fluttering
- Easily agitated, can’t sit down
Describe the typical hyperthyroidism patient
EMPHASIZED THIS
- If you see a younger female patient with symptoms, especially if they are in cardiology for irregular heart beat, it might be atrial fibrillation from hyperthyroidism
What is lid lag?
KNOW THIS
- “Lid lag” is a delay in downward movement of the upper eyelid as the patient looks down
- It is enhanced by the ophthalmopathy of Graves disease
Describe the eyes of a hyperthyroidism patient
Very typical eyes
Lid lag, weak eye muscles and excess collagen in the eye all make the eyes protrude forward
We call this exophthalmos and it causes proptosis
What is myxedema?
- Nodules confined to the anterior aspect of the legs (shins)
- Edema of the legs
- Usually seen in hypothyroidism, but can also be seen in hyperthyroidism sometimes
Describe the thyroid of a Graves’ patient
EMPHASIZED THIS
diffuse, symmetrical beefy red gland
** KNOW THIS WORD BY WORD **
What do you see at the molecular level?
KNOW SCALLOPING AND HYPERPLASTIC FOLLICLES WITH PAPILLARY INFOLDINGS *** –> This is Graves disease
Describe the signs and symptoms of hypothyroidism
- Slowing of the mind and body –> Prime problem
- Myxedema
- Fatigue
- Constipation
- Menstrual irregularities
- Weakness
- Weight gain
- Decreased memory and mental acuity
- Facial and periorbital edema
- ENLARGED tongue ***
- Course, dry skin
- Decreased metabolism
What was the symptom of hypothyroidism that was EMPHASIZED?
ENLARGED TONGUE
- Can see notches on the side of the tongue
What is cretinism?
- Hypthyroidism presenting first in infancy or childhood
- Leads to stunted growth, mental retardation, etc.
- We screen for this at birth because it can be treated within 3 weeks of life to prevent problems
What is Hashimoto thyroiditis?
A common chronic progressive autoimmune thyroid disease
What does the thyroid of a Hashimoto’s patient look like?
EMPHASIZED THIS
- Diffusely enlarged thyroid where the capsule is intact and well demarcated
- The surface is PALE, YELLOW/TAN and FIRM ***
NOT beefy and red like in hyperthyroiditis
What are the signature cells seen in thyroid follicles of patients with Hashimoto thyroiditis (hypothyroidism)?
HURTHLE CELLS *****
- If you see Hurthle cells, it means Hashimoto’s
- It can happen in other disease states, but 90% of the time it is Hashimotos
Describe Hurthle cells
- Abundant eosinophilic, granular cytoplasm
- Metaplastic response (Metaplasia) due to ongoing injury
- The normal low cuboidal follicular epithelials is injured
EMPHASIZED THIS
What is De Quervian thyroiditis?
A PAINFUL, transient HYPERthyroidism that goes away by itself in a matter of weeks to months following an infection
Need to be able to recognize that it is not Graves disease even though T3/4 are high
What causes De Quervian thyroiditis?
Viral cause
- Generally secondary to a viral infection by mumps, adenoviruses, echo, coxackie
What is a Goiter?
- A non-nodular enlargement of the thyroid gland
- Seen more commonly in females (8:1)
What causes a Goiter?
EMPHASIZED THIS
- The thyroid’s ability to produce thyroid hormone is impaired
- The circulating levels of thyroid stimulating hormone (TSH) are very high because it is trying to signal T3/4 production
- The most common cause of a goiter worldwide is IODINE deficiency ***
- In the US, where the use of iodized salt is common, a goiter is more often due to the over- or underproduction of thyroid hormones or to nodules that develop in the gland itself
What is a colloid goiter?
- The precursor to a nodular goiter
- The follicles of the gland are enlarged and filled with colloid
What is a nodular goiter?
Over time, the colloid goiter may become nodular
Many patients eventually develop toxic multinodular goiter
How can you tell the difference between a goiter and a tumor?
CAPSULE - emphasized this!
- A neoplasm will not have a capsule
- A goiter will be encasulated
What can a multinodular goiter result in?
A disease resembling Graves disease (hyperthyroidism) but without exopthalmos or dermatropathy
- You will see increase size and lobulation of the thyroid gland
What is the gold standard for diagnosing a thyroid neoplasm?
Biopsy
What is the difference between a “hot” neoplasm and a “cold” neoplasm?
- Hot = the mass will accumulate increased amounts of radioiodine during a scan
- Cold = the thryoid will not take up aditional radiolabeled iodine during a scan
What are thyroid adenomas?
EMPHASIZED THIS
- A neoplasm of the thyroid that does NOT have a tendency to become malignant
- It is capsulated
- It is a single structure
- It is most common in female adults
KNOW THIS ***
What are the four categories of thyroid cancers?
- Papillary (65%) - majority won’t die
- Follicular (25%)
- Medullary (5%) - from parafollicular C cells
- Anaplastic (5%) - almost all will die
PFMA (best to worst)
What is a key feature of the first type of thyroid cancer? Papillary thyroid carcinoma (PTC)?
Orphan Annie eyes
- Pathologists will see this
- This is what the nucleus looks like
Intranuclear cytoplasmic inclusion
- You will also see intranuclear grooves which make it look like a coffee bean
Psammoma bodies
EMPHASIZED THIS
What is a characteristic of follicular thyroid carcinoma?
EMPHASIZED THIS
- Metastases to the lungs and bone
- NO mets to the lymphatics
- NO orphan annie ies or psammoma bodies
Where does a medullary thyroid carcinoma originate from?
NEED TO KNOW
- C cells, which are parafollicular cells
- We do nor have good treatment for this kind of cancer
How would you describe anaplastic carcinoma?
VERY ugly, both histoligcally and clinically
Almost all will die
