2: Pathology of pituitary and adrenal glands Flashcards
Pituitary pathologies are caused by what two types of abnormal function?
Hyperfunction
Hypofunction
Which recess of the middle cranial fossa is the pituitary gland found in?
Sella turcica
What membrane of dura mater covers the pituitary gland?
Diaphragm sellae
Which structure connects the pituitary to the hypothalamus?
Pituitary stalk
Which pituitary gland is
a) an extension of the neural aspect of the hypothalamus?
b) anterior?
a) posterior
b) anterior
What is the anterior pituitary also known as?
Adenohypophysis
Which hormones does the anterior pituitary secrete?
Trophic: TSH, ACTH, LH and FSH
Non-trophic: GH and PRL
Which hormones does the posterior pituitary secrete?
ADH
Oxytocin
What is the posterior pituitary also known as?
Neurohypophysis
On histology of the pituitary gland, all the cells look different - why is this?
Loads of different cells which produce different hormones
What causes anterior pituitary hyperfunction?
Pituitary tumours
Adenomas and carcinomas
What causes anterior pituitary hypofunction?
Surgery, radiation
Haemorrhage into gland
Tumours
Inflammatory conditions
What is Sheehan syndrome?
What kind of abnormal pituitary function does it cause?
Ischaemic necrosis of pituitary gland following childbirth
Pituitary hypofunction
What are two notable conditions associated with the posterior pituitary?
Diabetes insipidus
SIADH
What is a benign tumour of the anterior pituitary known as?
Pituitary adenoma
What genetic syndrome are numerous pituitary adenomas a presentation of?
MEN1
multiple endocrine neoplasia
Pituitary adenomas are classified by the type of ___ they produce.
hormone
Can pituitary adenomas produce more than one hormone?
Yes
Do pituitary adenomas have to produce hormone?
No, similarly to thyroid, some are non-functional
Why may large pituitary adenomas cause visual field defects?
Compression of optic chiasm
What disease involves multiple hormone deficiencies of the pituitary gland?
Panhypopituitarism
Why may large pituitary adenomas cause hypopituitarism?
(Infarction due to) compression
What are three types of pituitary adenoma and which diseases will they cause?
Prolactinoma - hyperprolactinaemia (galactorrhoea, infertility, loss of libido, amenorrhoea)
GHoma - acromegaly
ACTHoma - Cushing’s disease
What are three causes of panhypopituitarism?
Tumours (primary or metastatic)
Granulomatous disease e.g sarcoidosis
Sheehan syndrome
The anterior pituitary gland is a remnant of which embryological structure?
Rafke’s pouch
Which rare, benign tumour is most commonly seen in children and arises from Rafke’s pouch during development?
Craniopharyngioma
What are two important posterior pituitary syndromes?
Diabetes insipidus
SIADH
Production of ectopic hormone e.g ADH, ACTH may be caused by what?
Functioning tumours elsewhere e.g small cell carcinomas of the lung
“Paraneoplastic syndrome”
What are the two parts of the adrenal gland?
Cortex
Medulla
The adrenal medulla is an extension of the ___ nervous system.
sympathetic
What hormones do the adrenal
a) cortex
b) medulla
produce?
Adrenal cortex - cortisol (glucocorticoids), aldosterone (mineralocorticoids), androgens (sex hormone)
Adrenal medulla - adrenaline and noradrenaline (catecholamines)
Again, what two types of abnormal adrenal function are there?
Hyperfunction
Hypofunction
Adrenal disease can be caused by which other endocrine gland?
Pituitary gland
What are three causes of adrenal cortex hyperfunction?
Hyperplasia (too much ACTH stimulation)
Adenoma, carcinoma
What are diseases causing acute and chronic adrenal cortex hypofunction?
Acutely - Waterhouse-Friederichsen disease
Chronic - Addison’s disease (the important one)
What is Waterhouse-Friderichson syndrome?
Adrenal hypofunction
caused by bleeding secondary to infection
usually Neisseria meningitidis
What causes adrenal cortex hyperplasia?
Overstimulation by ACTH
Which diseases are associated with overproduction of ACTH?
Which adrenal pathology is associated with this?
Cushing’s DISEASE
2ndary hyperaldosteronism
Ectopic ACTH production e.g small cell carcinoma of lungs
Androgen excess
ADRENAL HYPERPLASIA
Why are adrenal cortex adenomas yellow?
Lipid content
How do adrenocortical carcinomas tend to spread?
Locally - to retroperitoneum, kidneys
Haematogenously - to liver, lungs and bone
What syndromes do overproduction of
a) aldosterone
b) cortisol
by the adrenal cortex tumours produce?
a) Conn’s syndrome
b) Cushing’s syndrome
mind that pituitary ACTH excess causing symptoms would be Cushing’s disease and secondary hyperaldosteronism
Problems with which axis can cause secondary adrenocortical hypofunction?
Hypothalamic-pituitary-adrenal axis
Which type of drug suppresses the adrenal cortex?
Steroids
What is the name given to chronic adrenocortical insufficiency?
Addison’s disease
Addison’s disease is a type of (primary / secondary) adrenocortical insufficiency.
primary adrenocortical insufficiency
Which part of the nervous system innervates the adrenal medulla?
Sympathetic
Which cells in the adrenal medulla secrete catecholamines?
Neuroendocrine / Chromaffin cells
What are two types of tumour found in the adrenal medulla?
Phaeochromocytoma
Neuroblastoma
Which type of endocrine tumour is common in infancy?
Neuroblastoma
Craniopharyngioma
What is a neoplasm of neuroendocrine cells called?
Phaeochromocytoma
What cardiovascular disease does phaeochromocytoma cause?
Hypertension
(secondary)
What is a lab sign of phaeochromocytoma?
Urinary excretion of catecholamines
makes sense cuz you’re overproducing them
Phaeochromocytoma is known as the __% tumour.
10% tumour
10% extra-adrenal
10% bilateral
10% malignant
10% familial (think MEN2A)
10% DON’T cause hypertension