Pituitary Disease

Question 1

Briefly describe endocrine diseases

Answer 1

1. Dysfunction of hormone secreting glands
2. Negative feedback regulation
   - control failure (secondary)
   - gland failure (primary)
3. Causes widespread, multi system effects

Question 2

What tumours are present and associated with Multiple Endocrine Neoplasia 1 (MEN1)?

Answer 2

• Tumours
  1. Parathyroid
  2. Pancreatic Islets
  3. Pituitary (anterior)
• associated tumours
  1. Adrenal cortex, carcinoid lipoma

Question 3

What glands and tumours are associated with Multiple Endocrine Neoplasia 2a (MEN2a)?

Answer 3

• tumours
  1. Parathyroid
  2. medullary thyroid
  3. Phaeochromocytoma

Question 4

What tumours are associated with Multiple endocrine neoplasia 2b (MEN2b)?

Answer 4

1. Medullary thyroid Carcinoma
2. phaeochromocytoma
3. Mucosal neuromas

Question 5

What difference in control is there between the anterior and posterior pituitary gland?

Answer 5

The anterior pituitary can only be stimulated via vascular control whereas the posterior pituitary can be stimulated by vascular and neurological control

Question 6

What complications can arise from head trauma that may affect the pituitary gland?

Answer 6

The stalk connecting the pituitary gland to the base of the brain can close off due to head trauma which will cause an infarction of the pituitary gland

Question 7

What other anatomical feature could be affected by tumour growth around the pituitary gland?

Why is this?

What effects could this cause

Answer 7

• The optic chiasma
• put under pressure by tumour growth as any tumours will grow upwards due to pressure of the surrounding bone.
• this affects vision

Question 8

What are the main functions of the pituitary gland?

Answer 8

1. Control of many gland activities
2. Hypothalamic control - releasing hormones:
   - thyroid releasing hormone
   - gonadotropin releasing hormone
   - corticotropin releasing hormone
3. Hormones from the pituitary act directly on tissues to cause effect
   - e.g thyroid, growth hormone

Question 9

What hormones does the posterior pituitary associate itself with?

Answer 9

1. Anti Diuretic Hormone

2. Oxytocin

Question 10

What hormones are secreted from the anterior pituitary gland?

Answer 10

1. TSH - thyroid stimulating hormone
2. ACTH - adrenocorticotrophic hormone
3. GH - growth hormone
4. LH, FSH, Prolactin

Question 11

What hormones are secretes by the posterior pituitary gland?

Answer 11

1. ADH

2. Oxytocin

Question 12

What condition can be caused by insufficient production of ADH?

Answer 12

Diabetes insipidus

Question 13

What type of pituitary tumour usually causes dysfunction?

Answer 13

Adenomas

• functional
• non functional

Question 14

What two types of functional adenomas are there and what do they cause?

Answer 14

1. <40 years of age prolactin/ACTH
   - amenorrhoea-Galctorrhoea syndrome
   - Cushing’s disease
2. > 40 years of age growth hormone
   - acromegaly

Question 15

When do non functional adenomas appear and what do they cause?

Answer 15

1. > 60 years of age
   - cause mass effects
   . Visual field defects, other hormone deficiencies

Question 16

What is the most effective surgery for pituitary tumours?

Answer 16

Trans-sphenoidal surgery

- access is made through the sphenoid bone behind the nose, meaning the skull does not have to be opened

Question 17

What complications can arise from insufficient growth hormone?

Answer 17

1. Growth failure in children
2. Metabolic changes in adults
   - increased fat
   - reduced vitality

Question 18

How is secretion if growth hormone controlled?

Answer 18

1. Growth hormone secretion is controlled by the hypothalamus
   - Growth hormone releasing hormone (GHRH) released from the hypothalamus is essential to stimulate growth hormone release from the pituitary gland
   - growth hormone acts on the body tissues to produce anabolic reactions
   - insulin-like growth factor (IGF-1) is released from these tissues
   - IGF-1 has a positive feedback on the tissues, but a negative feedback on the pituitary gland which helps control growth hormone secretion

Question 19

What substance is most useful for measuring growth hormone levels due to the length of time it persists in the circulation?

Answer 19

insulin-like growth factor (IGF-1)

Question 20

What complications can arise from excess growth hormone?

Answer 20

1. ‘Giantism’ In children
2. Acromegaly in adults
   - growth plates have closed so only certain parts of the body can grow (e.g hands, feet, forehead and jaw)

Question 21

Why is it important to be extra vigilant for signs of acromegaly?

Answer 21

1. Insidious onset
   - early changes are subtle and it takes time for them to be made evident
   - if diagnosed late then changes are irreversible and patient will have an altered appearance

Question 22

When is the peak incidence of acromegaly?

Answer 22

30-50 years of age

Question 23

What are general presenting changes associated with acromegaly?

Answer 23

1. Coarse features
2. Enlarged supra-orbital ridges
3. Broad nose, thickened lips and soft tissues
4. Enlarged hands
   - results in carpel tunnel syndrome due to pressure on the nerves = finger numbness
5. Type 2 diabetes mellitus
   - due to resistance to insulin because of increased IGF-1 levels

Question 24

What general cardiovascular Changes are associated with acromegaly?

Answer 24

1. Cardiovascular disease
   - ischaemic heart disease due to extra strain of supporting larger mass
   - acromegalic cardiomyopathy die to the heart growing in size and becoming less efficient as a pump

Question 25

What are intraoral changes that are associated with acromegaly?

Answer 25

1. Enlarged tongue
2. Interdental spacing
3. ‘Shrunk’ dentures
4. Reverse overbite