Thyroid Pathology Flashcards
What are the mechanical and functional consequences of thyroid disease?
Mechanical:
- Goitre
- Compression effects (airway, oesophagus, large vessels)
Functional:
- Hyperthyroidism
- Hypothyroidism
- EUthyroidism
What is the most common cause of hypothyroidism in infacy/early childhood?
What cna it cause?
Usually caused yb dietary iodine deficiency.
Causes impaired development of skeleton and CNS (short statue, mental impairment)
What are the major causes of hypothyroidism for adults?
Primary problem with the thyroid:
- Inflammatory thyroiditis
- Autoimmune thyroiditis (Hashimoto’s)
- Primary iodine deficiency
In which demographics does hypothyroidism most frequently occur
- >60y.o.
- Women (Autoimmune thyroiditis is far more common in women)
What is the consequence of chronic hypothyroidism?
Myxedema - slowing of mental and physical activity
- Fatigue
- Cold intolerance
- Overweight
- Decreased cardiac output
- Decreased sympathetic activity
What is Hashimoto’s thyroiditis?
What are the pathological findings?
Autoimmune disease - loss of self-tolerance to thyroid antigens
- Female predominance
Patholigical findings:
- Apoptosis of epithelial cells
- Atrophy
- Fibrosis
What is thyrotoxicosis?
Hyperthyroidism
What are the symptoms of thyrotoxicosis for younger and older patients?
Young patients tend to exnhibit symptoms of sympathetic activation, older patients have more cardiovascular symptoms:
- Nervousness, anxiety, hyperactivity
- Heat intolerance
- Palpitations
- Tachycardia, hypertension
- Muscle weakness
- Weight loss despite increased appetite
What are the three most common causes of hyperthyroidism?
- Diffuse hyperplasia (Graves disease)
- Hyperfunctional multionodular goitre
- Hyperfunctiona thyroid adenoma
Are most carcinomas functional or non-functional?
Most are non-functional.
What is Grave’s disease?
Autoantibodies against TSH receptor and other thyroid antibodies.
Thyroid can become very large, with functional symptoms.
What are the symptoms characteristic of Grave’s disease?
- Pretibial myxedema
- Opthalmopathy (periorbital oedema, lid lag)
What is nodular colloid goitre and what does it cause?
Iodine deficiency = reduced hormone production.
Thyroid follicles are stimulated to work harder, inducing hyperplasia.
Cycles of hyperplasia lead to nodule formation - multinodular colloid goitre.
How do most nodular colloid goitres present in terms of thyroid hormone production?
Euthyroid
- However, it is the most common cause of thyroidectomy in Australia as it can cause hyperthyroidism
Describe the pathological presentation of most thyroid neoplasms
- Most present as solitary nodules
- Most are non-functional
What are the two types of thyroid adenomas?
Which is more common?
- Follciular adenoma (most)
- Hurthle cell adenoma
What are the path features of thyroid adenomas?
- Solitary nodules
- Well circumscribed and encapsulated
- Normal background thyroid
- No invasion
- Majority are non-functional
What is the treatment for thyroid adenomas?
Hemithyroidectomy.
What are the 4 types of thyroid carcinomas and their prevalence?
- Papillary (80%)
- Follicular (15%)
- Anaplastic (2%)
- Medullary neuroendocrine (3%)
How does follicular carcinoma typically look like?
Similar to follicular adenoma:
- Solitary nodule
- Thickly encapsulated
However:
- Capsular invasion
- Lymphovascular invasion
- Extrathyroidal extension
Is papillary carcinoma usually multifocal or solitary nodule?
Multifocal
Prognosis of papillary and follicular carcinoma?
Treatment?
Good.
Treatment = complete thyroidectomy
Which is the most aggressive form of thyroid cancer with a very poor prognosis?
Anaplastic thyroid carcinoma
- Aggressive
- Often preceded by follicular or papillary carcinoma
- Multifocal
