Pituitary disease and adrenal disease

Question 1

Classify pituitary adenomas according to size and function

Answer 1

Prolactinoma (40- 50%)

• SIZE: In younger women, most 10mm. In men and elderly women, many >10mm
• Hormonal signs and symptoms:
  
  • Galactorrhoea
  • Amenorrhoea
  • Hypogonadism
  • Erectile Dysfunction

GH secreting tumour (20%)​

• SIZE: Mm to Cm
• Hormonal signs and symptoms:
  
  • Change in appearance, increase in height.
  • Acromegaly/Gigantism

ATCH secreting tumour (10-15%)

• SIZE: Majority <10mm
• Hormonal signs and symptoms:
  
  • Cushing’s disease

TSH secreting tumour (rare)​

• SIZE: Most >10mm
• Hormonal signs and symptoms:
  
  • Hyperthyroidism

Non-functioning (20%)

• SIZE: ​Most >10mm at presentation
• Hormonal signs and symptoms:
  
  • Hypopituitarism
  • Mechanical S/s.

Question 2

What is a pituitary adenoma?

How are they classified?

Answer 2

• Benign tumours of the glandular tissue in the pituartary
  
  • Can be life threatening due to mass effects or secretory action
• Tumours <1cm are classified as microadenomas
• Tumours >1cm are classified as macroadenomas
• Classidied as ‘functioning’ or ‘non-functioning’ (silent) on the basis of whether they are secretory or nor

Question 3

What are the local symptoms that result from a large pituitary adenoma?

(the non-functioning adenoma presentation)

Answer 3

Local symptoms are caused by impingement or pressure upon surrounding structures

• Bitemporal hemianopia: compression of the optic chiasm
• Ocular palsies: compression of cranial nerves III, IV & VI
• Hypopituitarism: destroys the normal functioning tissue
• Signs of raised ICP: headache
• Hypothalamic compression symptoms: altered appetite, thirst, sleep/wake cycle

Question 4

What are the systemic clinical consequences of pituitary adenoma?

(functioning adenoma presentation)

Answer 4

Think about what hormones are released by the pituitary

• Acromegaly: excessive GH production
• Hyperprolactinaemia: excessive prolactin production
• Cushing’s syndrome: excessive ACTH production

Tumours secreting LH, FSH and TSH are rare.

Question 5

What hormones are released by the adenohypophysis? (anterior pituitary)

Answer 5

• Growth hormone
• Prolactin
• Adrenocorticotropic hormone (ACTH)
• Thyroid stimulating hormone (TSH)
• Gonadatrophin luteinizing hormone (LH)
• Follicle stimulating hormone (FSH)

Question 6

What hormones are released by the neurohypophysis? (posterior pituitary)

Answer 6

• Anti-diuretic hormone (ADH)
• Oxytocin

Question 7

What is Cushing’s syndrome?

What are its causes?

Answer 7

Cushing’s syndrome describes the symptoms of increased circulating glucocorticoid

• ACTH dependent causes:
  
  • Cushing’s disease
    
    • Increased ACTH from anterior pituitary (65%)
  • Ectopic ACTH
    
    • Non-pituitary ACTH secreting tumour (10%) (classically small-cell lung cancer)
• ACTH independent causes:
  
  • Excess adrenal cortisol production
    
    • Due to an adrenal tumour or nodular hyperplasia: 25%
    • Subsequent physiological ACTH suppression

Question 8

What are the major clinical and biochemical features of Cushing’s syndrome?

(signs and symptoms)

Answer 8

10 F’s

1. Feelings (depression, mood swings, psychosis)
2. Fuzzy (acne, hirsutism - excessive hair growth)
3. Fluid retention = raised BP
4. Fat - central obesity, buffalo hump, striae, intrascapula + suprascapular fat pads
5. Fragile - bruising, osteoporosis, thin skin
6. Frail - proximal muscle weakness
7. Females - amenorrhea
8. Fasting glucose up - diabetes, impaired glucose tolerance
9. Funny electrolytes
10. inFection - failure to heal e.g. ulcers

Symptoms:

• Central weight gain
• Change in appearance
• Depression
• Insomnia
• Poor libido
• Thin skin/easy bruising
• Excess hair growth/acne
• Diabetes symptoms

Signs:

• Moon face
• Frontal balding
• Striae
• Hypertension
• Pathological fractures
• ‘Buffalo hump’ (dorsal fat pad on back of neck)
• Proximal myopathy

Question 9

What is Addison’s disease?

What are its causes?

Answer 9

• Primary adrenal insufficiency
• Destruction of the entire adrenal cortex leading to glucocorticoid (cortisol), mineralocorticoid (aldosterone), and sex-steroid deficiencies
• This differs from hypothalamic-pituitary (HPA) disease as HPA disease generally spares mineralocorticoid production, which is stimulated by ATII (sex steroids are also largely independent of pituitary stimulation)

Causes:

• Autoimmune: 80% in the UK
• TB: most common cause worldwide
• Overwhelming sepsis
• Metastatic cancer: lung/breast
• Lymphoma
• Adrena haemorrhage
  
  • Waterhouse-Friderichsen syndrome

Question 10

What are the signs and symtoms for addison’s disease?

Answer 10

Symptoms: (often vague and non-specific)

• Weight loss
• Malaise
• Weakness
• Myalgia (muscle pain)

Signs:

• Pigmentation, especially of new cars and palmar creases
• Postural hypotension
• Signs of dehydration
• Loss of body hair (paticularly axillary/pubic)

Question 11

What is Conn’s syndrome?

Answer 11

• Adrenal adenoma leading to primary hyperaldosteronism (excess production of aldosteronism from adrenal glands)
  
  • (Conn’s syndrome is responsible for primary hyperaldosteronism in 60% of cases)
• Hyperaldosteronism leads to sodium and water retention

Question 12

How does Conn’s syndrome present?

What are its biochemical features?

Answer 12

Presentation:

• Mostly asymptomatic
• Hypertension
  
  • resistant to treatment
  • may causes headaches
• Features of hypokalaemia
  
  • May cause cramps, weakness, tetany
  • May be polyuria

Biochemical features:

• Hypokalaemia, with urinary potassium loss
• Elevated plasma aldosterone:renin ratio
  
  • Plasma aldosterone levels will not be suppressed by fludrocortisone administration

Question 13

What is phaeochromocytoma?

Answer 13

A neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth,that secretes high amounts of catecholamines, mostly norepinephrine, plus epinephrine to a lesser extent