A4- Pituitary Gland Flashcards
Hormones in the anterior lobe and posterior lobe?
Anterior lobe:1. Prolactin
- ACTH
- TSH
- GH
- LH
- FSH
Posterior lobe:
- Vasopressin
- Oxytocin
Classification of pituitary adenomas by pathology is
Examples of pituitary tumours?
- Pituitary adenoma
- Craniopharyngioma
- Meningioma
- Hypothalamic astrocytoma/glioma
Pituiatry adenoma
Presenting symptoms due to
- Hormonal dysfunction
• Underproduction (hypopituitarism)
• Hormonal hypersecretion - Local tumour growth and pressure effect
Hypopituitarism
What deficiencies does it include?
- GH deficiency
- Gonadotrophin deficiency: loss of libido, loss of secondary sexual characteristics, menstrual dysfunction, ED
- ACTH deficiency: hypocortisolism
- TSH deficiency: secondary hypothyroidism
- Vasopressin deficiency: diabetes insipidus
Ix for pituitary
Basal hormone measurement?
- Prolactin
- TSH, fT3 and fT4.
- Cortisol, ACTH
- LH, FSH, tesosterone or oetsradiol
- IGF1
Ix for pituitary
Dynamic hormone measurement
- TRH stimulation
- GnRH stimulation
- Glucagon test
- Dexamethasone suppression test
- Oral glucose tolerance test with GH measurement
Cushing’s syndrome symptoms/presentation?
• Moon facies
• Facial plethora
• Supraclavicular fat
pads
• Buffalo hump
• Truncal obesity
• Weight gain
• Purple striae
•Proximal muscle weakness
•Easy bruising
•Hirsutism
•Hypertension
•Osteopenia
•Diabetes mellitus/IGT
• Impaired immune
function/poor wound healing
Cushing’s syndrome vs. Cushing’s disease
• Cushing’s syndrome is a syndrome due to excess cortisol
from pituitary, adrenal or other sources (exogenous
glucocorticoids, ectopic ACTH, etc.)
• Cushing’s disease is hypercortisolism due to excess
pituitary secretion of ACTH (about 70% of cases of
endogenous Cushing’s syndrome)
Medical management of pituitary tumours
Which pharmacologic option to choose depends on
type of tumor:
• Dopamine agonists: bromocriptine, cabergoline- most
useful for prolactinomas, less useful for GH secreting
adenomas
• Somatostatin analog (Octreotide, Octreotide LAR)-most useful for acromegaly
• Pegvisomant (GH receptor blocker)- useful in
acromegaly refractory to somatostatin analogues
• Other: ketoconazole, metyrapone, mitotane- for
Cushing’s disease- use limited by side effects, expense and lack
of efficacy
Indications for intervention pituitary tumours
- Tumour growth on imaging
- Hormonal hypersecretion
- Visual field defects
Pituitary surgery options?
Transphenoidal approach:
used for 95% of pituitary tumors
Indications for Surgery for Pituitary tumours
- Surgery is the first-line treatment of symptomatic pituitary adenomas.
- Useful when medical or radiotherapy fails
- Surgery provides prompt relief from excess hormone secretion and mass effect.
- Indicated in pituitary apoplexy with compressive symptoms
Complications of Transsphenoidal
Surgery
Pituitary tumours
Indications for radiotherapy
- Incomplete resection of tumours
- Progressive disease after surgery
- Recurrent tumours
Pituitary tumours
Genetic predisposition?
- MEN type 1 syndrome
- Familial isolated pituitary adenoma (FIPA)
Most common • Enteropancreatic tumours?
Gastrinoma 40%
Most common Anterior pituitary tumours
Prolactinoma
What is Pituitary apoplexy
Apoplexy means bleeding into an organ or loss of blood flow to an organ. Pituitary apoplexy is commonly caused by bleeding inside a noncancerous (benign) tumor of the pituitary. These tumors are very common and are often not diagnosed. The pituitary is damaged when the tumor suddenly enlarges.
