CBL 10. A PATIENT WITH HEADACHES AND SWEATING Flashcards
Q1. What could be the cause of these constellations of symptoms? Are there any further specific questions you would ask? What areas of the clinical examination are important?
- Large tongue
- Large protruding jaw (prognathism)
- Galactorrhoea: due to raised prolactin
- Increase in shoe size
- Features of pituitary tumour: hypopituitarism, headaches, bitemporal hemionopia
- Lower voice
- Thyroid nodules or goitre
- ## Neurologica test - Full CN (checking vision) and PNS (carpal tunnel)
What additional tests would you like to see? [3]
CBG
ECG
Urine Dip
Old photos
Give some differentials for this patient
Pheochromocytoma
Conns Syndrome
Thyrotoxicosis
RA or SLE- joint pain
Meningitis
MSK / OA
Pinns and needles
Carpal tunnel syndrome
Saturday night palsy - compression of the radial nerve
Describe the physiology of GH release [4]
GHRH released from hypothalamus, goes to AP
GHRH stimlates the release of GH at AP
GH causes release of IGF-1 in a pulsatile manner
Somatostatin is a negative regulator of GH secretion
What cause accounts for 90% of cases of acromegaly? [1]
Pituitary adenomas
State three rarer causes of acromegaly (asides from pituitary adenomas) [3]
- Ectopic release of GH due to neuroendocrine tumours (e.g. pancreatic islet cell tumour)
- Ectopic release of GHRH due to carcinoid and small cell lung cancer
- Excess hypothalamic release of GHRH due to hypothalamic tumours
Ectopic release of GHRH is a rare cause of acromegaly. State two pathologies that could cause this [2]
Carcinoid and small cell lung cancer
Ectopic release of GH is a rare cause of acromegaly. State a pathology that could cause this [1]
Neuroendocrine tumours
His GP proceeds to a full clinical examination:
- Blood pressure 160/95 mmHg
This was the appearance of his face and hand.
His GP asks a local optometrist to measure his visual fields, below.
On the basis of this, his GP organises an urgent referral to the endocrine clinic
Q2. Explain these clinical findings.
Blood pressure (the following all contribute):
- ? reason - Increased peripheral vascular resistence causing increased fluid retention
- Higher risk of OSA
- CV disease
- Insulin resistance
Prognathism; macroglossia; frontal bossing: caused by the excess of growth hormone causing soft tissue and
Bitemporal hemionopia caused by the mass effect of the macroadenoma causing direct pressure on the optic chiasm
(Inside the circle you can see)
At the endocrine clinic, his history is confirmed. The endocrinologist is concerned about his pituitary gland.
Q3. How might pituitary disease present? What is the commonest form of pituitary tumour and how does it present?
Commonest form of pituitary tumour: prolactin-secreting pituitary adenomas. These present with
- galactorrhea
- decreased libido
- breast tenderness
- bitemp. hemniopia
- headaches
- infertility
- reduced muscle mass in men
- oligomenorrhea or amenorrhea
- olfactory problems
Prolactinomia
Osteoporosis
Q4. What investigations would you do to undertake baseline tests of pituitary tumour
Endocrine hormones screen:
- Gonodal axis: Men: LH, FSH, Testosterone, SHBG; Women: LH, FSH, oestradiol, progesterone (day 21 if menstruating) SHBG
- GH: GH & IGF-1
- Prolactin: on two occasions & with relaxation if elevation suspected
- Thyroid axis: TSH, fT4,
- Adrenocortical axis: serum cortisol (9am), plasma ACTH in specific cases, 24 hr urinary free cortisol
- Posterior pituitary: paired plasma and urine osmolality
Q4. What investigations would you do to undertake baseline tests of prolactinoma
Serum prolactin (anytime of day)
- elevated
A gadolinium-enhanced MRI of the pituitary
computerised visual-field examination
- may reveal unilateral or bi-temporal hemianopia
Q5. What are the causes of a raised prolactin? What do the above investigations, along with the clinical findings suggest is the likely diagnosis? What further investigations are required to confirm the diagnosis?
‘Physiological’ causes of raised prolactin:
- Pregnancy
- Lactation
- Stress
- Macroprolactinaemia: this refers to prolactin of high molecular mass, mostly complexes of monomeric prolactin with immunoglobulins (prolactin autoantibody complexes); these larger molecules have low bioactivity and a prolonged clearance rate similar to that of immunoglobulins.
Intracranial causes:
- Pituitary tumours: macro/microadenomas
- Head injury (eg, due to disruption of the pituitary stalk).
- Brain surgery and radiotherapy.
- Post-ictal - within hours of a seizure.
Endocrine and metabolic causes
* Hypothyroidism (due to increased synthesis of TRH).
* Cushing’s syndrome.
* Liver cirrhosis.
* Polycystic ovary syndrome.
Drugs:
* Dopamine receptor antagonists - eg, domperidone, metoclopramide, neuroleptics/anti-psychotics
* Dopamine-depleting agents - eg, methyldopa.
* Antidepressants - eg, tricyclic antidepressants, monoamine-oxidase inhibitors, serotonin reuptake inhibitors.
* Verapamil (affects 8.5% of patients).
* Opiates.
* Protease inhibitors.
* Bezafibrate.
* Omeprazole.
* H2-receptor antagonists.
Q5. What are the causes of a raised prolactin? What do the above investigations, along with the clinical findings suggest is the likely diagnosis? [1]
What further investigations are required to confirm the diagnosis? [3]
Raised IGF-1 indicates acromegaly secondary to macroadenoma pituitary tumour
Further investigations:
- IGF-1 levels (show normal variation whatever time taken, whereas GH goes up and down). If high confirms diagnosis and can perform imaging
- If IGF-1 levels equivocal: perform an oral glucose tolerance test. Give patient 100g of gluocose. Serum GH is measure before and after administration; Glucose should suppress GH release
- Pituitary MRI
Q6. How would you interpret the above results? What is the diagnosis? What therapeutic options are available?
Raised oral glucose tolerance test indicates acromegaly
