Pathology of Endocrine Disease Flashcards
RECAP- what are the four main glands of the endocrine system?
Thyroid gland
Parathyroid gland
Adrenal glands
Pancreas
RECAP- what controls the four main glands of the endocrine system?
Pineal gland
Hypothalamus
Pituitary gland
-> hypothalamus is CEO, pituitary is general manager
RECAP- what does the pineal gland produce?
Melatonin
Hypertropy?
Increased number and secretory activity of cells
Atrophy?
Reduction of cells due to lack of stimulation
What can cause tissue damage?
Inflammation, autoimmune disease, compression, trauma, infarction
Neoplasia?
Uncontrolled growth, either benign or malignant
What is meant by a functioning adenoma compared to a non-functioning adenoma?
Functioning adenoma produces hormones, it is a secretory tumour
Describe from a pathological POV what a benign neoplasm would look like down a microscope.
Often circumcised, localised, cannot invade and does not usually transform
Describe from a pathological POV what a malignant neoplasm would look like down a microscope.
Synonymous with cancer
Invades, metastasises
If untreated, fatal
All endocrine glands are regulated through the feedback mechanism.
Where do these always loop trhough?
The hypothalamus
Pituitary
Target organ
Most endocrine organs have a high reserve capacity. What does this mean in terms of clinical presentation?
Often late to present, often organs are damaged by up to 70%
Where is the pituitary gland located?
Sella turcica
How is the pituitary gland connected to the hypothalamus?
Via pituitary stalk
RECAP- the anterior pituitary is the biggest part of the pituitary gland.
Which hormones does it secrete?
ACTH- adrenal cortical trophic hormone
TSH- thyroid stimulating hormone
GH- growth hormone
LH/FSH
Prolactin
RECAP- what hormones does the posterior pituitary gland produce?
ADH
Oxytocin
What is the most common cause of pituitary hyperfunction?
Pituitary adenoma
If a pituitary adenoma is-
1. functional
2. non-functional
what will happen?
- Will secrete hormones
- Will increase in size
If a pituitary tumour is secreting GH, what could this cause as a result?
Acromegaly
Gigantism
If a pituitary tumour is secreting ACTH, what could this cause as a result?
Cushing’s disease
Prolctinoma?
Noncancerous tumour of the pituitary gland which secretes prolactin
If a pituitary tumour is secreting prolactin, what could this cause as a result?
Galactorrhoea
Menstrual disorders
Galactorrhoea?
Nipple discharge in someone who is not pregnant
What can cause pituitary hypofunction?
Compression by a tumour
Trauma
Infection
What is the function of the thyroid gland?
Synthesis, storage and release of thyroxine (T4) and triiodothyronine (T3)
Regulates basal metabolic rate.
Also synthesis, storage and release of calcitonin which regulates calcium homeostasis
Which has a longer half life, T3 or T4?
T4
Which more potent, T3 or T4?
T3
What is the most common cause of hyperthyroidism?
Grave’s disease
Who tends to be affected more by Grave’s disease?
Female > male
Peak 20-4oyrs
Genetic predisposition
RECAP- what happens in Grave’s disease?
Autoimmune production of anti-TSH receptor antibodies
What is the most common cause of hypothyroidism?
Hashimoto’s thyroiditis
->autoimmune destruction
->other causes = drugs, iodine deficiency
What is Hashimoto’s thyroiditis?
Autoimmune destruction of thyroid epithelial cells
Who is more likely to get Hashimoto’s thyroiditis?
Female> male
45-65yrs
Describe follicular carcinomas.
Enlarged follicle epithelial cells, mirco-follciular architecture and they have a capsule.
Localised and do not invade
What is the most common differentiated thyroid carcinoma?
Papillary carcinoma (75-85%)
Followed by follicular carcinoma (10%)
How are thyroid nodules investigted?
TFT’s
Ultrasound
FNA cytology
->hope you know FNA is fine needle aspiration x
What are some of the risk factors for thyroid carcinoma?
FH
Chronic inflammatory episodes
Radiation exposure
Obesity
What is the only difference between a follicular adenoma and follicular carcinoma?
A follicular carcinoma has capsular breach and vascular invasion
-> carcinoma is malignant
How and where does a follicular carcinoma metastasise to?
Via blood to bone
Typically, how old are patients with papillary carcinoma, the most common type of thyroid carcinoma?
<50yrs
What is the associated mutation to papillary carcinoma?
BRAF mutation
RET/PTC gene rearrangement
What is papillary carcinoma associated with?
Exposure to ionising radiation
How does a papillary carcinoma spread?
Via lymphatics
What is the prognosis like for papillary carcinomas?
Very good
What is a medullary carcinoma?
Malignant tumour of C-cells
What does a medullary tumour produce and secrete?
Calcitonin
-> +/- other polypeptides
What has an opposing inhibitory mechanism on parathyroid hormone?
Calcitonin
->works the other way too, each inhibit each other
If there is parathyroid hyperfunction caused by an adenoma, how much parathyroid glands are affected?
1
If there is parathyroid hyperfunction caused by hyperplasia, how much parathyroid glands are affected?
4
Parathyroid hyperfunction is usually sporadic. It can be familial in which syndrome?
MEN-1
Secondary hyperparathyroidism can be as a result of what?
Renal failure
-> decrease in calcium level because kidneys are not functioning.
Feedback so not enough calcium = overproduction of PTH
How would someone get multiple endocrine neoplasia (MEN)?
Inherited disorder with underlying genetic mutation
What is MEN-1 also known as?
Wermer syndrome
What is a MEN-1 tumour caused by?
Tumour suppressor gene mutation meaning there is a defect in the protein involved in cell growth
What can this MEN1 tumour suppressor gene lead to?
Parathyroid hyperplasia and adenomas
Pancreatic and duodenal endocrine tumours
Pituitary adenoma
-> three P’s
If a tumour is secreting insulin, what type of symptoms will the patient have?
Hypoglycaemic symptoms
What causes MEN-2?
Mutation in the RET gene
->this mutation drives mutations and neoplasia
What are two clinical manifestations of MEN-2?
Medullary carcinoma of the thyroid
Pheochromocytoma
MEN-2A has the same clinical manifestations (medullary carcinoma of the thyroid and pheochromocytoma) as well as one other. What is it?
Parathyroid hyperplasia
MEN-2B has the same clinical manifestations as MEN2 (medullary carcinoma of the thyroid and pheochromocytoma) as well as two others. What are they?
Neuromas of skin and mucous membrane
Skeletal abnormalities
Who is more likely to be affected by MEN-2B?
Younger patients
More aggressive
