The Pituitary Gland - Clinical Case & Discussion

Question 1

What is the normal pituitary anatomy and neuro-endocrine control of pituitary secretion?

Answer 1

1. Anterior (endocrine) and posterior (neuronal tissue) pituitary
2. Is connected to the hypothalamus by the infundibulum
3. Releasing hormones are secreted from the hypothalamus via neuronal stimulation.
4. These releasing hormones act on the anterior pituitary to secrete the stimulating hormones which act on the target endocrine organ.

Question 2

What is the clinical presentation and biochemical diagnosis of pituitary hyperfunction syndromes (Acromegaly)?

Answer 2

1. Acromegaly:
   
   1. Clinical presentation
      
      1. Spade-like hands
      2. Large, wide feet
      3. Coarse facial features
      4. Large tongue (too big for mouth)
      5. Sweating
   2. Diagnosis
      
      1. Oral glucose test
         
         1. After taking an oral glucose load, acromegalic patients will show elevated levels of GH in the blood and elevated blood glucose levels compared to normal patients

Question 3

What is the clinical presentation and biochemical diagnosis of pituitary hyperfunction syndromes (Cushings)?

Answer 3

1. Cushing’s Disease:
   
   1. Clinical presentation
      
      1. Moon-shaped face
      2. Muscle wasting of extremities
      3. Excessive abdominal fat with thin legs and arms.
      4. Pink stretch marks around abdomen
      5. Skin atrophy
      6. Spontaneous purpura – red spots on the skin
      7. Osteoporosis
   2. Diagnosis
      
      1. ACTH levels and cortisol levels measured after dexamethasone administration
      2. 24 hour urinary measurement for cortisol levels

Question 4

What is the clinical presentation and biochemical diagnosis of pituitary hyperfunction syndromes (Prolactinoma)?

Answer 4

1. Prolactinoma:
   
   1. Clinical presentation
      
      1. Milk production
      2. Infertility and impotence
      3. Visual field abnormalities
      4. Headache
   2. Diagnosis
      
      1. Blood prolactin levels

Question 5

What are the clinical features of hypopituitarism in adults and children?

Answer 5

1. Adults – Tiredness, weight gain, depression, loss of libido, impotence, skin pallor, reduced body hair
2. Children – Reduced linear growth and delayed puberty

Question 6

How are neoplasms of the endocrine system classified in terms of functional or non-functional?

Answer 6

1. Functional Neoplasms:
   
   1. The secretions of the neoplasm (tumour) lead to clinical symptoms
2. Non-functional neoplasms:
   
   1. The neoplasm does not secrete any hormones, therefore it does not lead to any clinical symptoms.

Question 7

What are the consequences of a space occupying lesion in the pituitary region?

Answer 7

1. Bilateral hemianopia
2. Space occupying lesion could be seen by MRI imaging

Question 8

What is the clinical management of patients with pituitary disease?

Answer 8

1. Pituitary surgery – A good option for patients with non-functioning neoplasm of the pituitary and Cushing’s disease. Surgery passes through the sphenoid sinus.
2. Hypersecretion – Somatostatin analogues (acromegaly), GH receptor antagonists (acromegaly), dopamine agonsists (prolactinoma)
3. Hyposecretion – Cortisol, T4, sex steroids, GH