Thyroid Gland Pathology Flashcards
What are the cells lining the follicle?
Cuboidal or Columnar Epithelium
What do C cells secrete?
Calcitonin
What is the function of calcitonin
Calcitonin promotes absorption of calcium by the skeletal system and inhibits resorption of bone by osteoclasts
Thyrotoxicosis
Hyper metabolic state due to increased circulating levels of thyroid hormones due to any cause - often used interchangeably with hyperthyroidism
How does thyroiditis cause hyperthyroidism?
Destruction of the glands leads to release of pre-formed hormone that causes transient hyperthyroid episodes
What are the clinical features of hyperthyroidism?
- Increased BMR – soft warm flushed skin
- Heat intolerance and excess sweating
- Characteristic weight loss despite increased appetite
- Increased CO/tachycardia/palpitations
What tests can be used for Dx of hyperthyroidism?
- TSH levels - usually will be decreased
- T4 levels - usually increased
What is the TRH stimulation test used for?
Pituitary adenoma - normal rise in TSH after injection
of TRH excludes pituitary associated hyperthyroidism
Hypothyroidism
Hypometabolic state secondary to inadequate levels of thyroid hormones
What gender is more affected by hypothyroidism?
Females
What is the most common cause of hypothyroidism in 3rd world countries?
Iodine Deficiency
What is the most common cause of hypothyroidism in 1st world countries?
Chronic autoimmune thyroiditis (Hashimoto’s thyroiditis)
Cretinism
- Hypothyroidism in infants or early childhood
* Impaired development of skeletal muscles and CNS
Myxedema
- Adult hypothyroidism
- Gradual slowing of mental and physical activity
- Fatigue, lethargy, apathy, slowed speech
- Cold intolerance and reduced sweating
What lab findings with hypothyroidism show?
- Decreased T4
- Increased TSH
Hashimoto Thyroiditis
Characterized by gradual thyroid failure because of autoimmune destruction of the thyroid gland
What Ab will be found in Hashimoto thyroiditis?
- Thyroid Peroxidase Ab
- Thyroglobulin Ab
- TSH Receptor Ab
- Iodine Receptor Ab
- Diffusely enlarged gland
- Intact capsule
- Well demarcated from adjacent structures
- Cut surface is pale, yellow tan, somewhat nodular and firm
Hashimoto Thyroiditis