Endocrinology - Pituiatary and Hypothalamic Disorders

Question 1

Discuss the pathophysiology, presentation and management of acromegaly

Answer 1

Pathophysiology
- GH secreting adenoma
- Carcinoid
- increase GH results in proliferation of bone, cartilate, soft tissues, and organomegaly
- Leads to insulin resistance
Presentation
- Gigantism in children
- Enlarged hands, feet
- Coarsening of facial features
- Prognathism
- 2-3x increased cancer risk
Investigation
- Elevated IGF-1
- No GH suppression with 75g OGTT
- MRI of sella turicica

Question 2

Discuss the pathophysiology, presentation and management of hyperprolactinemia

Answer 2

Pathophysiology
- Most common pituitary adenoma
- Primary hypothyroidism
- Anti-dopaminergic drugs
Presentation
- Galactorrhea
- Infertility
- Hypogonadism
- Amenorrhea and erectile dysfunction
Investigation
- Serum PRL, TSH
- MRI of sella turcica
Management
- Long acting dopamine agonist: bromocriptine
- Surgery

Question 3

Discuss the presentation and investigations for pituitary adenoma

Answer 3

Presentation
- Bitemporal hemianopsia due to optic chiasm compression
- Diplopia due to oculomotor nerve palsy
- Headache
- Hypopituitarism
- Hyperfunction leading to galactorrhea, acromegaly, ACTH and cushing syndrome
Investigation
- MRI

Question 4

Discuss the eitiology of hypopituitarism

Answer 4

The Eight I's
Invasive
- pituitary tumours
Infarction/Hemorrhage
- Sheehan's syndrome: pituitary infarction due to excessive post-partum blood loss
- Pituitary apoplexy: aute hemorrhage/infarction of pituitary tumour resulting in loss of pituitary hormones
Infiltrative/Inflammatory
- Sarcoidoisis
- Hemachromatosis
Infectious
- Syphylis
- TB
Injury
- Head trauma
Immunologic
- autoimmune
Iatrogenic
- surgery or radiation
Idiopathic

Question 5

Discuss the presentation and investigation for hypopituitarism

Answer 5

Presentation related to Deficiency
- ACTH: Fatigue, weight loss, hypoglycemia, hyponatremia
- GH: short stature, increased fat
- TSH: tiredness
- LH/FSH: amenorrhea, infertility, decreased body hari and muscle mass, delayed puberty, erectile dysfunction
- Prolactin: inability to breastfeed
- ADH: diabetes insipidus
Investigation with Triple Bolus
- GnRH to increase LH and FSH
- Insulin to lead to hypoglycemia to increase GH and ACTH/cortisol
- TRH to increase TSH