Pathology of the pituitary and adrenal glands Flashcards
What is the embryological origin of the anterior pituitary?
Rathkes pouch
What are the trophic hormones?
TSH
ACTH
FSH
LH
What are the non trophic hormones?
GH
Prolactin
What is the embryological origin of the posterior pituitary?
Extension of neural tissue and modified gliacl cells and axonal processes
What does the posteiror pituiary secrete?
ADH
Oxytocin
What does the anteiror pituitary look like histologically?
Islands Cords of cells Aciodphils Basophils Chromophobe
What are the different types of aciodophils and what do they secrete?
Somatotrophs - GH
Mammotrophs - PRL
What are the different types of basophils and what do they secrete?
Corticotrophs - ACTH
Thyrotrophs - TSH
Gonadotrophs - FSH/LH
What does the posterior pituitary look like histologically?
Non-myelinated axons of neurosecretory neurones
What can cause hyperfunction of the anterior pituitary?
Adenoma
Carcinoma
What can cause hypofunction of the anterior pituitary?
Surgery/radiation Sudden haemorrhage into the gland Ischaemic necrosis - sheehan syndrome Tumours extending into sella Inflammatory conditions (sarcoid)
What are common pathologies of the posterior pituitary?
Diabetes insipidus
SAIDH
What can cause SIADH?
Ectopic secretion by tumours
Primary disorder of the pituitary
What causes diabetes insipidus?
Lack of ADH secretion
Life theratning dehydration
How are pituitary adenomas classed?
By the cell type/ hormone produced: Prolacinoma (20-30%) ACTH (10-15%) FSH/LH (10-15%) GH (5%) Hypo/non-functional (25-30%)
What other features can a large adenoma have?
Visual field defects
Pressure strophy of surrounding normal tissue
Infarction to panhypopituitarism
What will a prolactinoma cause?
Infertility
Lack of libido
Amenorrhoea
What will a GH secreting adnoma cause?
Growth of bone, cartilage and connective tissue causing gigantism or acromegaly
What will an ACTH secreting adenoma cause?
Cushings disease
Bilateral adrenocortical hyperplasia
What can cause panhypopituitarism?
Granulomatous inflammation - sarcoidosis
Infarction - sheehan’s syndrome
Primary or metastatic tumours
What is the origin of a craniopharyngioma?
Rathke’s pouch
What is the growth like of a craniopharyngioma?
Slow growing, cystic, calcification
What are the common symptoms of a craniopharyngioma?
Headaches and visual disturbances - children may have growth retardation
What are the different types of diabetes insipidus?
Central - ADH deficiency, trauma
Nephrogenic
Where does the adrenal gland sit?
Superior and medial to the upper pole of the kidneys
What is the adrenal gland composed of?
Outer cortex and central medulla
What can adrenal pathology be a manifestation of?
Pituitary disease
Shock/DIC
What can cause hyperfunction of the adrenal cortex?
Hyperplasia
Adenoma
Carcinoma
What can cause hypofunction of the adrenal cortex?
Acute: waterhouse friderichsen
Chronic: addisons
What is waterhouse friderichesen?
Adrenal gland failure due to bleeding into the adrenal glands, commonly caused by severe bacterial infection. Typically it is caused by Neisseria meningitidis
What can congenital adrenocortical hyperplasia lead to?
Increased androgen production – masculinisation, precocious puberty
What can cause endogenous ACTH production?
Pituitary adenoma (cushings) Ectopic ACHT - paraneoplastic syndorme such as in small cell lung cancer
What can cause acquire adrenocortical hyperplasia?
Endogenous ACTH production
Bilateral adrenal enlargement
Diffuse or nodular
In what condition can an adrenocortical tumour occur in children?
Li-Fraumeni syndrome - germline mutation of p53
What is the presentation of adrenocortical tumours?
Incidental finding
Hormonal effects
Mass lesion
Carcinomas with necrosis can cause fever
What will an adrenocortical adenoma look like?
Well cirumscribed - encapsulated lesion
Small
Yellow/brown cute surface
What will the cells look like in adrenocortical adenomas?
Cells resembling adrenocorticl cells
Well differentiated, small nuclei, rare mitoses
Where will adrenocortical carinomas spread?
Localy - retroperitoneum, kidney
Metastasis - liver, lung and bone
Peritoneum and pleura
Regional lymph nodes
What are the survival rates for adrenocortical carcinomas?
5 year survival is 20-35%
50% dead in 2 years
What features suggest an adrenocortical tumour?
Large size Haemorrhage and necrosis Frequent mitosis, atypical mitoses Lack of clear cells Capsualr or vascualr invasion
What is primary hyperaldosteronism?
Conn’s syndrome
What are the presenting features of conn syndrome?
Hypokalaemia - fatigue, numbness, increased urination, increased thirst, muscle cramps, muslce weakness
What will an adenoma causing primary hyperaldosteronism look like?
Solitary, small, bright yellow
Buried within the gland
Spiranolacton bodies
Do not supress ACTH so adjacenet and contralateral adrenal tissue is not atrophic
What are the different types of cushings syndrome?
Cushings disease
Endogenous - ACTH dependent, ACTH independent
What can cause adrenocortical hypofunction?
Failure to simulate adrenal cortex - hypothalamic-pituitary disorder
Supression of adrenal cortex - treatment with steroids
What causes acute primary adrenocortical insufficiency?
Rapid withdrawel of steroid treatment
Crisis in patients with chronic adrenocortical insufficiency due to stress - infection, no increasing dose of steroid treatment
Massive adrenal haemorrhage
What can cause massive adrenal haemorrhage?
Newborn
Anticoagulant treatment
DIC
Septicaemic infection -waterhouse friderichsen
What can cause chronic primary adrenocortical insufficiency?
Addison’s disease
What can cause addisons disease/
Autoimmune
Infections - TB, fungal (histplasma), HIV (kaposi’s sarcoma)
Metastatic malignancy (lung, breast)
Amylid, sarcoid, haemachromatosis
What are the symptoms of addisons disease?
Weakness, fatigue, anorexia, N+V, Wt loss, diarrhoea
Pigmentation (raised POMC)
What biochemical signs will addisons show?
K+ retention
Na+ loss
Hyperkalaemia, hyponatraemia, volume depletion, hypotension
Hypoglycamia
What will an addisonian crisis show?
Stress - infection, trauma or surgery
Vomiting, abdo pain, hypotension, shock and death
What innervates the adrenal medulla?
Pre-synaptic fibres from the sympathetic nervous system
What cells make up the adrenal medulla?
Neuroendocrine (chromaffin) cells
What tumours affect the adrenal medullar?
Phaeochromocytoma
Neuroblastoma - paeds
When are neuroblastomas commonly diagnosed?
18 months
What causes a neurblastoma?
Amplification of N-myc and expression of telmoerase
What is a phaeochroomocytoma?
Neoplasm derived from chromaffin cells of the adrenal medulla
Secrete catecholamines
Secondary hypertension
What paroxyxsmal episodes of hypertension are common in a phaeo?
Stress, exericse, posture, palpation of tumour
What are complications of a phaeochromocytoma?
Cardiac failure
Infarction
Arrhythmias
CVA
What is the lab diagnosis of a phaechromocytoma?
Detection of urinary exretion of catecholamines and metaboltes
Where will extre-adrenal phaeochromocytomas be?
Paragangliomas
Organs of zuckerkandl
What is the rule of 10% of a phaeo?
10% extra-adrenal 10% bilateral 10% biologically malignant 10% NOT associated with hypertension 25% familal
What is teh organ of zuckerkandl?
Chromaffin body derived form neural crest located at the bifurcation of the aorta or at the origin of the inferior mesenteric artery
What will the adrenal gland look like if there is a phaeochromocytoma?
Yellow, red/brown to haemorrhagic and necrotic
If the phaeochromocytoma is metastatic where will it commonly metastasize to?
Skeletal
Regional lymph nodes
Liver
Lung
What is MEN2A?
Sipple syndrome;
Phaeochromocytoma, medullary thyroid carcinoma and parathyroid hyperplasia
What is MEN2B?
Phaeochromocyoma, medullary htyroid carcinoma, neuroma or ganglioineuromas and marfanoid habitus
What are the 3 zones of the adrenal cortex?
Zona glomerulosa - mineralocorticoids, aldosterone
Zona fasciculata- glucocorticocids, cortisol
Zone reticularis - sex steroids, glucorticoids
