Endocrinology Flashcards
Features of acromegaly
Excess GH secondary to pituitary adenoma
Coarse features, spade like hands, increased shoe size
Large tongue, interdental spaces
Excessive sweating
Features of a pituitary tumour- hypopituitarusm, headache, bitenporal hemianopia
Raised prolactin
MEN-1
Complications of acromegaly
HTN
Diabetes
Cardiomyopathy
CRC
Investigations for acromegaly
Serum IGF-1 level/serial GH measurements (1st line)
OGTT- hyperglycaemia should suppress GH (not in acromegaly)- OGTT used to confirm diagnosis
MRI head- tumour
Management of acromegaly
Trans sphenoidal surgery
Or a somatostatin analogue eg. Octereotide (inhibits release of GH) for GH secreting tumours if surgery not possible/fails
Hypomagnesia and hypocalcaemia
Hypomagnesia can cause hypocalcaemia and render treatment such as vitamin D and calcium ineffective- need to treat the hypomagnesia first
Side effects of glucocorticoids
Endocrine- impaired glucose regulation, increased appetite, weight gain, hirsutism, hyperlipidaemia
Cushing’s syndrome- moon face, buffalo hump, striae
MSK- osteoporosis, proximal myopathy, a vascular necrosis of femoral head
Immunosuppression
Psych- mania, depression, psychosis
GI- peptic ulceration, acute pancreatitis
Ophthalmic- glaucoma, cataracts
Growth suppression, neutorphilia, intracranial HTN
Mineralcorticoid side effects
Fluid retention
HTN
Long term steroid use
Double corticosteroid dose (not fludrocortisone- mineralocorticoid) during inter current illness
Gradual withdrawal of systemic corticosteroids if patients have had more than 40mg daily for more than a week, or received more than 3 weeks treatment
NB- don’t stop for any reason. Always discuss with doctor!!
Causes of hypercalcaemia
2 conditions account for 90%- primary hyperparathyroidism (most common in community- solitary parathyroid adenomas). Malignancy is most common in hospitalised patients
Sarcoidosis
Vitamin D excess
Acromegaly
Thyrotoxicosis
Thiazide drugs
Dehydration
Addison’s disease
Pagers disease of bone (usually normal but can see an increase if immobilised due to condition)
Primary hypoparathyroidism
Decreased PTH secretion (eg. Due to thyroid surgery)
Low calcium, high phosphate
Treated with alfacalcidol
Main symptoms are of hypocalcaemia (inc. prolonged QT)
NB- main symptoms are due to hypoparathyroidism
Klienfelters syndrome
Karyotype 47, XXY
Features
Taller than average, lack of secondary sexual characteristics, small firm testes, infertile, gynaecomastia, elevated gonadotropin levels (FSH and LH) but low testosterone, obese
Diagnosis is karyotype (chromosomal analysis)
Multiple endocrine neoplasia (MEN)
MEN1- hyperparathyroidism (hypercalcaemia), pituitary, pancreas (insulinoma, gastrinoma, recurrent peptic ulceration)
MEN2a- medullary thyroid cancer, parathyroid, phaeochromocytoma
MEN2b- medullary thyroid cancer, phaeochromocytoma, neuromas, Marfinoid body habitus
Neuroblastoma
Childhood malignancy arising from adrenal medulla and sympathetic nervous system
Abdominal mass, pallor, weight loss, bone pain, hepatomegaly, paraplegia, proptosis
Raised urinary VMA and HVA
Primary hyperparathyroidism
PTH elevated
Calcium elevated
Phosphate low
Secondary hyperparathyroidism
PTH elevated
Calcium low or normal
Phosphate elevated
Vitamin D low
NB- parathyroid hyperplasias
Phaeochromocytoma
HTN
Headaches
Sweating
Palpitations
Anxiety
Test- 24 hour urinary collection of metanephrines
Surgery is the definitive management. The patient must first however be stabilized with medical management:
alpha-blocker (e.g. phenoxybenzamine), given before
beta-blocker (e.g. propranolol)
Treatment for hyperparathyroidism
Total parathyroidectomy
Cinacalet if surgery not appropriate (mimics action of calcium)
Dopamine and prolactin
Dopamine inhibits prolactin secretion from the anterior pituitary (dopamine agonists can be used to control prolactinomas eg. Bromocriptine, cabergoline)
Causes of a raised prolactin
Secretory pituitary adenoma
Pregnancy
Oestrogens
Stress, exercise, sleep
Acromegaly
PCOS
Drugs- metoclopramide, haloperidol, rarely- SSRI, opioids
Bone protection and steroids
Bone protection for patients who are going to take long-term steroids (ie. GCA) should start immediately (alendronic acid, vitamin D and calcium supplements)
X ray of primary hyperparathyroidism
Generalised osteopenia, erosion of the terminal phalyngeal tufts (acro-osteolysis) and sub-periosteal resorption of bone particularly the radial aspects of the 2nd and 3rd middle phalanges, pepper pot skull (p for p- Pepper for Parathyroid)
In terms of history;
Generalised aches and pain, polydipsia and lethargy are also common symptoms of having a raised calcium level.
Insulinoma features
Whipple’s triad of symptoms of 1) hypoglycaemia with fasting or exercise, 2) reversal of symptoms with glucose, and 3) recorded low BMs at the time of symptoms is hallmark for an insulinoma
What hormones are decreased during surgery
Insulin
Oestrogen
Testosterone
What hormones are increased during surgery
GH
Cortisol
Renin
ACTH
Prolactin
ADH
Glucagon
What hormones don’t change during surgery
TSH
LH
FSH
Kallman syndrome
Hypogonadotropic hypogonadism
‘delayed puberty’
hypogonadism, cryptorchidism
anosmia
sex hormone levels are low
LH, FSH levels are inappropriately low/normal
patients are typically of normal or above average height
Infertile
Cleft lip/palate and visual/hearing defects are also seen in some patients
Differentiate Klinefelters from Kallmans
Kline every mountain;
gonadotrophins (LH/FSH), stature are all increased/high
NB- testosterone low in both
Tertiary Hyperparathyroidism
Due to prolonged CKD/secondary hyperparathyroidism
High PTH
High/normal calcium (secondary- low/normal)
Cushing’s disease
Due to an ACTH producing pituitary tumour (cortisol suppressed by dexamethasone but plasma ACTH is high)
The tumour is often too small to see on an MRI so a normal scan does not exclude it
Acromegaly and prolactinomas
Prolactinomas- treat medically, then surgically
Acromegaly- treat surgically, then medically
Causes of a raised prolactin
Causes of raised prolactin - the p’s
pregnancy
prolactinoma
physiological
polycystic ovarian syndrome
primary hypothyroidism
phenothiazines, metoclopramide, domperidone
Severe hyponatraemia (<120)
Treat with hypertonic saline eg. 3%
