Histo: Endocrine disease Pt.3

Question 1

What is the most common cause of secondary hyperparathyroidism?

Answer 1

Renal failure

• Parathyroid can be enlarged
• Leads bone disease as with primary disease

Can be caused by any condition with chronic calcium depression

Question 2

List some causes of hypoparathyroidism.

Answer 2

• Surgical ablation
• Congenital absence
• Autoimmune

Question 3

List some clinical features of hypoparathyroidism.

Answer 3

• Neuromuscular irritability - paresthesia, muscle spasm, tetany
• Cardiac arrhythmias
• Seizures
• Cataracts

CATs go numb

Question 4

Which cell types constitute the cortex and medulla of the adrenal gland?

Answer 4

Cortex = epithelial

Medulla = neural

Question 5

What are the layers of the adrenal cortex and which hormones do they produce?

Answer 5

• Glomerulosa - aldosterone
• Fasciculata - glucocorticoids
• Reticularis - sex steroids

Question 6

Which conditions causes adrenal hyperfunction?

Answer 6

• Cushing’s syndrome - excess glucocorticoids
• Hyperaldosteronism (Conn’s)
• Virilising syndrome - excess androgens

Question 7

What is the most common cause of Cushing’s syndrome?

Answer 7

Iatrogenic - administration of exogenous corticosteroids (leads to adrenal atrophy)

Question 8

What happens to the adrenal glands in Cushing’s disease?

Answer 8

Undergo nodular hyperplasia of the cortex

Question 9

List 4 endogenous causes of Cushing’s syndrome.

Answer 9

• Cushing’s disease - ACTH producing pituitary adenoma (> 50%)
• Adrenal adenoma/carcinoma
• Adrenal hyperplasia
• Ecotopic ACTH production - small cell lung cancer

Question 10

What are the clinical features of Cushing’s syndrome?

Answer 10

• Hypertension
• Weight gain
• Truncal obesity
• Moon face
• Buffalo hump
• Cutaneous striae

Question 11

What are the causes of hyperaldosteronism?

Answer 11

• 35% adenoma (Conn’s syndrome)
• 60% bilateral adrenal hyperplasia

Question 12

List the two main clinical features of hyperaldosteronism.

Answer 12

• Hypertension
• Hypokalaemia

Question 13

What causes virilising syndromes?

Answer 13

• Neoplasms (more commonly carcinoma than adenoma)
• Congenital adrenal hyperplasia

Question 14

Describe the pathophysiology of congenital adrenal hyperplasia.

Answer 14

• Autosomal recessive
• Hereditary defect in an enzyme involved in cortisol synthesis leads to cortisol deficiency
• This leads to increased ACTH release from the pituitary gland
• ACTH stimulates adrenal hyperplasia and androgen synthesis

Question 15

What is the most common cause of CAH?

Answer 15

21-hydroxylase deficiency

Question 16

List three causes of acute primary adrenal failure.

Answer 16

• Sudden withdrawal of corticosteroid treatment
• Haemorrhage (neonates)
• DIC associated with sepsis (Waterhouse-Friderichson syndrome)

Question 17

List some causes of chronic primary adrenal failure. (UK)

Answer 17

• Autoimmune (90%)
• TB
• HIV
• Metastatic tumour (lung and breast)
• Amyloid, fungal infection, haemochromatosis, sarcoid (very rare)

Question 18

What are some secondary causes of adrenal insufficiency?

Answer 18

• Non-functional pituitary adenoma
• Pituitary/hypothalamic lesions including infarction

Question 19

What are the two types of adrenocortical neoplasm?

Answer 19

• Adenomas - mostly functional, may be associated with Cushing’s syndrome or Conn’s syndrome
• Carcinomas - rare, more commonly associated with virilisng syndromes than adenomas

Question 20

What are the two types of tumours of the adrenal medulla?

Answer 20

• Phaeochromocytoma
• Neuroblastoma

Question 21

What is the rule of 10s regarding phaeochromocytomas?

Answer 21

• 10% associated with a familial syndrome (MEN)
• 10% bilateral
• 10% malignant
• 10% oustide the adrenal gland (paraganglioma)

Secrete catecholamine and causes a surgically correctable form of hypertension

Question 22

Define multiple endocrine neoplasia and its inheritance.

Answer 22

A group of autosomal dominant conditions resulting in proliferative lesions (hyperplasia, adenoma, carcinoma) of multiple endocrine organs

Question 23

Outline the characteristics of tumours in MEN.

Answer 23

• Tend to occur at a younger age
• Tend to arise in multiple endocrine organs or may be multifocal within one organ
• Often preceded by hyperplasia
• Usually more aggressive than sporadic tumours

Question 24

What are the different types of MEN and the tumours associated with them?

Answer 24