Endocrinology Flashcards
Static test
These can diagnose abnormalities of thyroid and sex glands
Stimulation tests
For suspected hormonal under-secretion
Suppression test
For suspected hormonal over-secretion
What is over-secretion of endocrine glands usually due to
Benign tumours
What is under-secretion due to
Gland destruction due to:
inflammation
infarction
other
Prolactin over secretion and clinical presentation
A relatively common condition
Usually due to a pituitary tumour secreting prolactin (prolactinoma)
Clinical presentation
Galactorrhoea (breast milk production)
Amenorrhoea in women and sexual dysfunction in men
Headaches and visual field problems in large tumours
What might mildly raised prolactin be due to?
Sexual intercourse
Nipple stimulation
Stress
Large number of drugs (including antipsychotics and antidepressants)
Non-functioning pituitary tumour (compressing the hypothalamus and interfering with the inhibitory effect on prolactin secretion)
What does growth hormone excess result in children?
Excessive growth spurt and increased size of feet and hands
If left untreated growth hormone excess leads to gigantism, the most serious consequence of the disease
What does growth hormone excess result in adults?
Acromegalic face
Wide and large hands/feet
Increased sweating (common complaint)
What might cushing’s syndrome be due to?
Pituitary secreting ACTH tumour (Cushing’s disease)
Adrenal tumours secreting cortisol
Cancers producing ACTH (such as lung cancers)
What is the clinical presentation of cushion’s syndrome
Growth arrest in children Round (moon-like) face Acne Hirsuitism Fat redistribution Truncal obesity Thin extremities Skin abnormalities Thin skin and easy bruising Striae on abdomen Complications: Hypertension Diabetes mellitus High risk of infections Poor wound healing
Breast cancer
There are two versions of the oestrogen receptor, ERa and ERb
Healthy breast tissue normally expresses more ERB than ERa
Some type of breast cancer strongly express ERa
Oestrogen promotes rapid division of ERa- positive breast cancer cells
ER-positive breast cancers (ER+) can be detected by staining sections of tumour biopsies with antibodies against the oestrogen receptor
The growth and spread of these cancers can be inhibited by administering anti-oestrogen drugs such as tamoxifen
Why is hyperthyroidism more common in women?
The main cause is auto-immune diseases, which are more common in women
What are the causes if hyperthyroidism?
Graves disease (80%)
Toxic nodule or toxic MNG (15%)
Thyroiditis (1%)
Drug induced (amiodarone)
What is the clinical presentation of graves disease?
Hyperactivity, irritability, insomnia Heat intolerance and increased sweating Palpitations Weight loss despite overeating Menstrual problems
