Lesson 1E (Part 3) Flashcards
Follicular neoplasm
Encapsulated true neoplasms of the thyroid gland
- 5-10% of all thyroid nodules
What is differentiation of follicular adenoma from a follicular carcinoma based on?
The presence of capsular or vascular invasion on histologic examination
- cannot be made by sonography or by FNA cytology
What does follicular adenomas and follicular carcinomas look like sonographically? (2)
- Solitary encapsulated tumors
2. Well-defined peripheral hypoechoic halo representing the fibrous capsule
What kind of follicular neoplasms are considered minimally invasive?
The types that are encapsulated
What kind of follicular neoplasms are considered invasive?
Extends beyond the tumour capsule into blood vessels and adjacent parenchyma
What is the echogenicity of follicular neoplasms?
Variable
- echogenic
- isoechoic
- hypoechoic
How do echogenic adenomas appear?
- Smoothly marginated
- Ovoid in appearance
- Pseudotesticle
Medullary thyroid cancer
Neuroendocrine tumor arising from the parafollicular C cells located in the upper two thirds of the thyroid gland
What is the sonographic appearance of medullary carcinoma? (3)
- Solid
- Hypoechoic
- Coarse central calcifications
Anaplastic carcinoma
Is a rare (<1%) thyroid mass that is extremely aggressive
Who does anaplastic carcinoma affect?
The elderly with a history of goiter
How does anaplastic carcinoma present?
A rapidly growing neck mass
- tumor invades locally
How do anaplastic carcinomas appear sonographically? (6)
- Large
- at least 5 to 10 cm - Fixed
- not going to move/slide - Hard
- not compressible - Heterogeneous
- Internal calcifications and cystic or necrotic areas
- Adjacent enlarged lymph nodes
What are most thyroid lymphomas?
Non-Hodgkin lymphomas
How does lymphomas present itself?
With a rapidly enlarging painless neck mass
What is the sonographic appearance of lymphoma? (2)
- Very hypoechoic
- Pseudocystic pattern
- increased through transmission
What is the sonographic appearance of metastatic disease? (5)
- Nonspecific appearance
- Usually solid
- Noncalcified
- Hypoechoic nodules
- Can be hypervascular
Hyperparathyroidism
Excess secretion of parathyroid hormone
- usually by benign tumours of a gland
What does hyperparathyroidism cause?
The release of calcium from bones which raised the blood calcium levels
- hypercalcaemia
What are 5 effects of hyperparathyroidism?
- Polyuria and polydipsia
- Formation of renal calculi
- Anorexia and constipation
- Muscle weakness
- General fatigue
What are the 2 types of hyperparathyroidism?
- Primary
2. Secondary
Primary hyperparathyroidism
An enlargement of one or more of the parathyroid glands causes overproduction of the hormone, resulting in high levels of calcium in the blood
- hypercalcemia
What is primary hyperparathyroidism caused by?
A single adenoma
- 85% of cases
Primary
Is involved with the organ or system itself that is causing problems
Secondary hyperparathyroidism
Occurs as a result of another disease that initially causes low levels of calcium in the body and over time, increased parathyroid hormone levels occur
Secondary
Is involved with something outside the organ or system itself that is causing problems
Tertiary hyperparathyroidism
Is a state of excessive secretion of parathyroid hormone after longstanding secondary hyperparathyroidism and resulting in hypercalcemia
When does tertiary hyperparathyroidism persist?
After successful renal transplantation
What are causes of hyperthyroidism? (6)
- Medical conditions that cause low blood calcium levels or increased phosphate levels
- Conditions that make it hard for the body to remove phosphate
- Kidney failure
- Not enough calcium in the diet
- Vitamin D disorders
- Problems absorbing nutrients from food
What is the result of hyperparathyroidism? (4)
- Increased risk of bone fractures
- High blood pressure and heart disease
- Kidney stones
- Osteitis fibrosa
Hypoparathyroidism
Parathyroid hormone deficiency that causes hypocalcaemia, due to abnormally low blood calcium levels
Which parathyroid disorder is more common?
Hyperparathyroidism
What does low levels of blood calcium cause? (5)
- Tetany
- Psychiatric disturbances
- Paraesthesia
- Grand mal seizures
- In some cases, cataracts and brittle nails.
What causes hypoparathyroidism? (3)
- Damage to or removal of the glands during thyroidectomy
- Ionising radiation
development of autoantibodies to PTH and parathyroid cells - Congenital abnormality of the glands
What is tetany caused by?
Hypocalcaemia
Why is tetany caused by hypocalcaemia?
Because low blood calcium levels increase excitability of peripheral nerves
Tetany
Very strong painful spasms of skeletal muscles, causing characteristic bending inwards of the hands, forearms and feet
What us hypocalcaemia associated with?
Hypoparathyroidism
Hypocalcaemia
Is a deficiency of vitamin D or dietary deficiency of calcium that results in chronic renal failure when there is excretion of excess calcium in the urine
What does tetany affect?
The peripheral nerves
