Endocrine Pathology Flashcards
complications of diabetes?
- Atherosclerosis
- Susceptibility to infections
- microangiopathy
Pathogenesis of type 1?
- All have genetic susceptibility
- viral infection in children can disturb immune regulation
- auto reactive T-cells infiltrate islets and destroy beta cells
- Autoantibodies produced against B cell antigens can be detected
- beta cell loss becomes critical and resultant hyperglycaemia
Pathogenesis of Type II?
- Genetic and lifestyle (obesity)
- insulin resistance: peripheral tissue doesn’t respond to insulin
- beta cell dysfunction: inadequate insulin secretion when hyperglycaemia occurs and insulin resistance
What are the CV complications of diabetes?
- accelerated atherosclerosis
- increased incidence of MI and peripheral vascular arteriole disease
- autonomic neuropathy affects bodies response to MI (can often see silent MIs)
- peripheral vascular disease and peripheral neuropathy is what causes problems in feet
What are the renal complications of Diabetes?
- Vascular lesions: atherosclerosis of large and small vessels and efferent arteriole
- Glomerular lesions and glomerulosclerosis
- increased risk of pyelonephritis as susceptible to infections which can lead to papillary necrosis
Complication of diabetes in the eyes?
- Retinopathy
- Cataracts
- Glaucome
What is the main cause of Hyperpituitarism?
Anterior pituitary gland adenoma
can have functional (release hormones) and non functional tumours
What symptom could a macroadenome of pituitary gland cause?
- Peripheral vision loss due to compression of optic chiasma
- bitemporal i.e. on both sides
What is the optic chiasm?
Crossing over of the visual pathways
What will be the effects of Hyperprolactinaemia?
- Amenorrhea
- Galactorrhea
- loss of lipids
- Infertility
What are the types of adenohypophysial adenoma?
- Prolactinoma
- GH-secreting
- ACTH-secreting
What will the effects of excess Growth hormone release?
Acromegaly (adults)
- characterised by enlarged feet and hands, increased heel-pad thickness, coarse facial feature and large stature
- get hypertension and cardiomegaly also
Gigantism (children i.e. pre-epiphyseal plate fusion)
- similar to acromegaly
What are the causes of pituitary hypo function?
- macro non-functioning adenoma, metastatic carcinoma
- post-partum ischaemic necrosis of pituitary (Sheehans syndrome)
What are the effects of anterior pituitary syndrome?
- amenorrhea
- infertility (women)
- hypothyroidism
- hypoadrenalism
- Diabetes insipidus due to lack of ADH release
Causes of hypothyroidism?
- Hashimoto’s disease (autoimmune)
- iodine deficiency
- congenital defect where no thyroglobulin synthesised
- post-surgery removal of thyroid gland
- Drugs e.g. lithium
Causes of Hyperthyroidism?
- Grave’s disease
- hyper-functioning toxic goitre or adenoma (produce thyroxine)
- thyroiditis (inflammation of thyroid) can be lymphatic or granulomatous
- exogenous excess thyroid hormone e.g. when prescribed to treat hypothyroidism
Features of hyperthyroidism?
- Weight loss
- Tachycardia
- sweating
Features of hyperthyroidism?
- Weight loss
- Tachycardia
- atrial fibrillations
- sweating
- tremor
- oncholysis (nail bed)
- protruding eyes
What is Hashimoto’s thyroiditis?
- Lymphatic infiltration of thyroid follicles
- formation of reactive lymphoid follicles with germinal centres
- destroys thyroid follicular epithelium (become very pink staining)
Pathogenesis of Hashimoto’s thyroiditis?
- Anti-thyroid antibodies secreted by plasma cells cause cell-mediated cytotoxicity
- CD4+ cells activate macrophages to cause thyrocyte injury
- CD8+ T cells cause T-cell-mediated cytotoxicity
What is Graves disease?
- breakdown in the tolerance of thyroid auto antigens which produce autoantibodies
- autoantibodies increase thyroid stimulating immunoglobulins which bind to TSH receptor
- mimics impacts of TSH
What is Goiter?
- enlargement of thyroid gland
- can get some enlarged and some smaller hyperplastic follicles
- get haemorrhage
- can occur due to ingestion of foods which interfere with thyroxine biosynthesis
- can also occur due to congenital enzyme defect so thyroxine not synthesised
What symptoms can Goiter cause?
- difficulty breathing
- difficulty swallowing
- hoarseness (recurrent laryngeal nerve impacted)
Tumours of the thyroid Gland?
1) papillary carcinoma - distinctive nuclear features, metastases to regional lymph nodes
2) follicular carcinoma - similar to follicular adenoma but will have capsular and vascular invasion, metastases to lungs or bones
3) medullary carcinoma - neuroendocrine tumour, secretes calcitonin and other hormones, spreads locally to blood or lymph
What is Cushing syndrome?
- Cause: ACTH producing adenoma (Cushing disease)
- Cause: Adrenal cortical neoplasms
- get excess production of glucocorticoids
Symptoms of Cushing syndrome?
- hyperglycaemia
- acne
- red cheeks
- rounded face
- thinning hair
What is Conns syndrome?
- Primary hyperaldosteronism
- associated with bilateral nodular hyperplasia of adrenal glands
- excessive secretion of mineralocorticoids
- get hypertension and hyperkalaemia
What tumour of adrenal medulla can cause hypertensive crises during surgery?
Phaeochromocytoma
screened for by checking for urinary catecholamines
What is Waterhouse Friedrickson syndrome?
- caused by Meningitis
- disseminated intravascular coagulation
- haemorrhage into adrenal gland
- associated with acute adrenal dysfunction
What is Addisons disease?
- cause of chronic adrenocortical insufficiency
- autoimmune
- caused by: AIDS, tuberculosis or carcinoma
- associated with high ACTH levels and hyperpigmentation
Symptoms of Addisons?
- fatigue
- weakness
- GI disturbance
Causes of hyperparathyroidism?
Primary - hyperplasia of adrenal gland or PTH secreting adenoma
Secondary - inc in PTH in response to hypocalcaemia
Tertiary - development of autonomous hyper secreting adenoma in secondary hyperparathyroidism
