Pathology of the pituitary and the adrenal gland Flashcards
What is the adenohypophysis?
Anterior pituitary
What is the neurohypophysis?
Posterior pituitary
What trophic hormones does the anterior pituitary secrete?
Adrenocorticotrophic hormone
Follicular stimulating hormone
Luteinizing hormone
Thyroid stimulating hormone
What non-trophic hormones does the anterior pituitary secrete?
Growth hormone
Prolactin
What is a trophic hormone?
Hormones that act upon endocrine glands
What does the posterior pituitary secrete?
Anti-diuretic hormone/vasopressin
Oxytocin
What colour do acidic cells show up on H&E staining? What about alkaline cells?
Acidic - pink
Alkaline - purple
Are the cells which secrete the non trophic hormones acidic or alkaline?
Acidic (i.e pink)
Which pathologies of the anterior pituitary gland can cause hyperfunction?
Adenoma
Carcinoma
Which pathologies of the anterior pituitary gland can cause hypofunction?
Surgery Radiation Sheehan syndrome/ischaemic necrosis Haemorrhage Tumours Sarcoidosis (& other inflammatory conditions)
List some common pathologies of the posterior pituitary
Diabetes insipidus
Syndrome of inappropriate ADH secretion (SIADH)
What extra-pituitary cause is there for SIADH?
Paraneoplastic/ectopic production
What is diabetes insipidus?
Insufficient ADH secretion causing dehydration
Is pituitary adenoma associated with MEN1 or MEN2?
MEN1
How are pituitary adenomas classified?
Cell type/hormone produced
Which types of pituitary adenomas can you develop?
Prolactinoma ACTH-oma GH-oma FSH/LH-oma TSH-oma Mixed Hypofunctioning/non-functioning
Is it possible to have a pituitary adenoma with subclinical hormone production levels?
Yes
What are the mass effects of large pituitary adenomas?
Bitemporal hemianopsia
Pressure atrophy
Infarction –> panhypopituitarism
What is the most common functional pituitary adenoma?
Prolactinoma
How does a prolactinoma present?
Lack of libido
Amenorrhoa
Infertility
Growth hormone causes the production of which substance?
Insulin like growth factor 1
How does a growth hormone producing adenoma present?
Increased growth of bone, cartilage and connective tissue:
- Acromegaly (adults)
- Gigantism (children)
How does an ACTH producing adenoma present?
Cushing’s syndrome
What are the two commonest causes of Cushing’s syndrome?
Bilateral adrenal hyperplasia
ACTH secreting pituitary adenoma
Are pituitary carcinomas most commonly functional or non-functional?
Functional
List some possible causes of panhypopituitarism
Rathke cleft cysts Traumatic brain injury Subarachnoid haemorrhage Surgery Radiation Granulomatous inflammatory disease (sarcoidosis, TB) Sheehan's syndrome Apoplexy/bleeding from internal organ Hypothalamic tumours
How might a pituitary apoplexy present?
Headache Diplopia Hypopituitarism Cardiovascular collapse Loss of consciousness
Why might diplopia result in a pituitary apoplexy?
Haemorrhage puts pressure on the oculomotor nerve
Apart from panhypopituitarism what else might hypothalamic tumours cause?
Diabetes insipidus
What is a cricopharyngioma derived from?
Rathke’s pouch remnants
Are most cricopharyngiomas sellar or suprasellar in location?
Suprasellar
Which age groups do cricopharyngiomas present in?
Young*
Old
How do cricopharyngiomas present?
Headaches
Visual disturbances (nerve palsies, etc)
Growth retardation
How are cricopharyngiomas treated?
Radiation
What are the possible causes of central diabetes insipidus?
Trauma
Iatrogenic
Inflammatory disorders
Tumours
What is the cause of nephrogenic diabetes insipidus?
Renal resistance
What is the most common underlying cause behind syndrome of inappropriate ADH secretion?
Paraneoplastic syndrome
Where do the adrenal glands sit in relation to the kidneys?
Superior and medial
What are the two parts of the adrenal glands?
Outer cortex
Inner medulla
What type of hormone does the cortex secrete?
Steroid
What type of hormone does the medulla secrete?
Catecholamines
What are the three zones of the adrenal cortex?
Zona glomerulosa, fasiculata and reticularis (Get Fucked Robyn)
What do the zones of the adrenal cortex secrete?
Glomerulosa - mineralocorticoids
Fasiculata - glucocorticoids
Reticularis - sex steroids
Name a mineralocorticoid and a glucocorticoid
Aldosterone
Cortisol
Which type of cells secrete catecholamines?
Neuroendocrine/chromaffin
What is the adrenal medulla innervated by?
Pre-synaptic sympathetic nerve fibres
Which conditions not affecting the adrenals directly can affect adrenal functioning?
Pituitary disease
Shock
Disseminated intravascular coagulation
Is congenital adrenal hyperplasia autosomal dominant?
No autosomal recessive
How does congenital adrenal hyperplasia cause adrenal pathology?
Altered enzyme pathways cause an increase in androgen production
Reduced cortisol stimulates ACTH release and hyperplasia
How does congenital adrenal hyperplasia present?
Masculinisation
Precocious puberty
What are the underlying causes behind acquired adrenal hyperplasia?
Pituitary adenoma (cushing's) Ectopic ACTH (paraneoplastic)
What is the difference between nodular and diffuse acquired adrenal hyperplasia in terms of ACTH?
Diffuse usually ACTH dependent
Nodular usually ACTH independent
Which age group gets adrenal tumours?
Adults
In which condition do children get adrenal tumours?
Li-Fraumeni syndrome
How do adrenal tumours present?
Hormonal effects
Mass effects
Fever of unknown origin (carcinoma w/ necrosis)
Incidental
Are adrenal adenomas typically functional?
No
How common is adrenal cancer?
Rare
Are adrenal cancers typically functional?
Yes (virilising)
How does adrenal cancer typically spread?
Local
Vascular metastases
Peritoneum
Regional lymph nodes
What are the features of an adrenal mass that would suggest cancer?
Large >20cm
Haemorrhage +/- necrosis
Capsular or vascular invasion
Histological signs
What pathology of the adrenal glands is primary aldosteronism (conn’s) associated with?
Bilateral hyperplasia (common)
Adenoma
Glucocorticoid remediable
What is glucocorticoid remediable primary aldosteronism an is it ACTH linked?
Rare genetic disorder and yes
What is the underlying mechanism behind secondary aldosteronism?
Increased renin
What causes secondary aldosteronism?
Decreased renal perfusion
Pregnancy
Hypovolaemia
Hypercortisolism is endogenous. T/F
False - non specific term which can refer to endogenous or exogenous pathologies
What is the cause of exogenous hypercortisolism?
Steroid therapy (iatrogenic)
How can the endogenous causes of hypercortisolism be divided?
ACTH dependent
ACTH independent
What is cushing’s disease?
A ACTH secreting pituitary adenoma
What is the most common source of ectopic ACTH production?
Small cell lung cancer
What are the ACTH dependent mechanisms of hypercortisolism?
Cushing’s
Ectopic production
What are the ACTH independent mechanisms of hypercortisolism?
Adrenal adenoma
Adrenal carcinoma
Non-lesional atrophy
How can primary causes of adrenal insufficiency be divided?
Acute
Chronic
What are the acute causes of adrenal insufficiency?
Withdrawal of steroid treatment
Crisis induced in chronic insufficiency patients (e.g infeciton)
Adrenal haemorrhage
What are the causes of adrenal haemorrhage?
Newborn babies
Septicaemia –> waterhouse-fruderuchsen syndrome
Anticoagulation treatment
Disseminated intravascular coagulation
What are the chronic causes of adrenal insufficiency?
Addison's disease/autoimmune adrenalitis Infection (TB, fungal, HIV) Metastatic malignancy Amyloidosis Sarcoidosis Haemochromatosis
Does addison’s disease develop fast or slow?
Slowly
How does Addison’s disease present?
Weakness Fatigue Anorexia Vomiting Weight loss Diarrhoea Palmer pigmentation
Why does palmer pigmentation result in addison’s disease and no hypopituitarism?
Raised proopiomelanocortin only occurs in addison’s
What is the effect of decreased mineralocorticoids in addison’s disease?
Potassium retention
Sodium loss
Volume depletion
Hypotension
What is the effect of decreased glucocorticoids in addison’s disease?
Hypoglycaemia
How does an addison’s crisis present?
Inducted by stress (infection, trauma, surgery, etc) Vomiting Abdominal pain Hypotension Shock
When is a neuroblastoma diagnosed?
Children and infants
Where do neuroblastomas arise?
Adrenal medulla
Sympathetic chain
How is the prognosis of a neuroblastoma affected by age?
The younger the patient the better the prognosis
What is a phaeochromocytoma derived from?
Chromaffin cells of the adrenal medulla
What do phaeochromocytomas secrete and what can this cause?
Catecholamines
Secondary hypertension
How does a phaeochromocytoma present?
(Paroxysmal) hypertension (younger patients)
Aggravated by exercise, posture, stress
Micturation (bladder involvement)
What are the complications of phaeochromocytoma?
Heart failure
MI
Arrhythmia
CVA
How is phaeochromocytoma diagnosed?
Catacholeamines in urine
Why is phaeochromocytoma called the 10% tumour?
Bilateral Extra-adrenal Familial Malignant Not associated with hypertension
What are extra-adrenal phaeochromocytomas called and where are they found?
Paraganglioma
Carotid body
Where do cancerous phaeochromocytomas usually metastasise to?
Bone (common)
Lymph nodes
Liver
Lung
What are the two classifications of multiple endocrine neoplasia type 2?
Type 2A - Sipple syndrome
Type 2B
What mutation is multiple endocrine neoplasia type 2 associated with?
RET
What are the features of sipple sydrome?
Phaeochromocytoma
Medullary thyroid cancer
Parathyroid hyperplasia
What are the features of MENT2B?
Phaeochromocytoma
Medullary thyroid cancer
Marfinoid habitus
Neuroma/ganlioneuroma