Pituitary Flashcards by Aaron Duff

How can the causes of Cushing’s syndrome be divided?

ACTH and non-ACTH dependent Cushings

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What is the the pathological cause of the symptoms in Cushings?

Excess cortisol production by adrenal cortex, also excess mineralocorticoid and excess androgen

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What are some symptoms of Cushings syndrome?

Weight increase
Mood change
Proximal weakness
Gonadal dysfunction
Acne

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What are some signs of Cushings syndrome?

Central obesity
Plethora
Moon face
Buffalo neck hump
Thin skin
Bruising
Pigmentation
Hypertension
Abdominal striae
Osteoporosis

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What are the key clinical features of Cushing’s syndrome?

Pigmentation (only ACTH-dependent)
Cushingoid appearance (excess alcohol consumption-pseudo-Cushings)
Impaired glucose tolerance (especially ectopic ACTH syndrome)
Hypokalaemia (common with ectopic ACTH secretion), HT
Thin skin
Proximal myopathy
Frontal balding in women
Conjunctival oedema
Osteoporosis

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How is Cushings diagnosed?

Diagnosis

Tests-Many to choose from
Dexamethasone overnight suppression test is 1st line, followed by 48hr test.
Failure to suppress=Cushing’s syndrome,

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What are the causes of cushings?

Pituitary, adenoma of adrenal, ectopic-thymus, lung, pancreas, pseudo-alcohol and depression, steroid medication

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How can you differentiate between a pituitary, adrenal or ectopic cause of Cushings?

ACTH test- pituitary less than 300, ectopic more than 300, adrenal less than 1. In high dose dexam suppression pituitary will be suppressed by 50%, not seen in adrenal/ectopic

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What is the treatment for Cushings?

Pituitary-hypophysectomy and radiotherapy, adrenal-adrenalectomy, ectopic-remove source or bilateral adrenalectomy. Also Metyrapone, ketoconazole and fluconazole to decrease cortisol pre-op

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What toxicity can occur from keotconazole?

Hepatoxicity

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What are the hormonal effects of pan hypopituitarism?

Anterior pituitary-GH:growth failure, TSH-hypothyroidism, LH/FSH-hypogonadism, ACTH-hypoadrenal, Prolactin-none known

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What are some causes of hypopituitarism?

Pituitary tumours, secondary metastatic lesions (lung, breast), local brain tumours-(astrocytoma, meningioma, glioma), granulomatous disease, vascular disease, trauma, hypothalamic diseases (syphiilis, meningitis), iatrogenic-surgery, AI-Sheenan:post pregnancy, infection

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What are some features of hypopituitarism?

Menstrual irregularities
Infertility
Impotence
Gynaecomastia
Abdominal obesity
Loss facial hair, loss axillary &amp;pubic hair (M&amp;F)
Dry skin and hair
Hypothyroid faces
Growth retardation

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How are the adrenal glands stress response tested?

Synacthen test-ACTH stimulation

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What is the treatment for hypopituitarism?

Hormone replacement therapy- thyroxine, hydrocortisone, ADH, GH, sex steroids

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What are the effects of giving GH to adults?

Improves well being and QOL, decreased abdo fat, increases muscle mass, strength, exercise capacity and stamina, improves cardiac function, decreased cholesterol and increases LDL, increases bone density, given by daily SC injection

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What are the risks of testosterone replacement?

Prostate enlargement, polycythaemia, hepatitis (Only oral tabs)

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What are some causes of cranial Diabetes Insipidus?

Familial -isolated in most cases, can be part of DIDMOAD(DI, DM, optic atrophy, deaf). Acquired-idiopathic 50%, trauma-road accidents etc. Rare -tumour, sarcoid, irradiation, meningitis

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How do you diagnosis DI?

Water deprivation test

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How do you treat DI?

Desmopressin-spray, oral, sublingual, injection

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What is the peripheral hormone of ACTH?

Cortisol

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What is the peripheral hormone of TSH?

Thyroxine

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What is the peripheral hormone of LH/FSH?

Testosterone or Estradiol

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What is the peripheral hormone of GH?

IGF-1

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What is the peripheral hormone of Prolactin?

No peripheral hormone

How are pituitary tumours sized?

More than or equal to 1cm: Macroadenoma. Less than 1cm: Microadenoma

What can a Non-functioning pituitary adenoma cause compression on?

Optic chiasma, as well as other structures e.g. CN 3,4,6

What can a Non-functioning pituitary adenoma cause?

Hypoadrenalism, hypothyroidism, hypogonadism, DI, GH deficiency

What are some of the physiological causes of raised prolactin?

Breast feeding, pregnancy, stress, sleep

What are some drug causes of raised prolactin?

Dopamine antagonists e.g. metoclopramide, antipsychotics e.g. phenothiazines, antidepressants e.g. TCA, SSRIs, others-estrogens, cocaine

What are some pathological causes of raised prolactin?

Hypothyroidism, Stalk lesions-iatrogenic,- road accident, prolactinoma

What are some clinical signs and symptoms of prolactinoma in females?

Early presentation, galactorrhoa (30-80%), menstrual irregularity, amenorrhoea, infertility

What are some clinical signs and symptoms of prolactinoma in males?

Late presentation, impotence, visual field abnormal, headache, anterior pituitary malfunction

What investigations should you undertake in suspected prolactinoma?

Prolactin concentration, MRI pituitary, visual fields, pituitary function tests (other hormones affected?)

What are you looking for in a pituitary MRI?

Micro/macroprolactinoma (1cm), pituitary stalk, optic chiasma

What are you looking for in a visual fields investigation in suspected prolactinoma?

Bitemporal hemianopia, not homonymous hemianopia

What is the treatment for prolactinoma?

Dopamine agonists-bromocriptine, quinagolide (norprolac), cabergoline (dostinex): usual choice, least S/Es

What is acromegaly an excess of?

What are some signs and symptoms of acromegaly?

Giant (before epiphyseal fusion), thickened soft tissues-skin, large jaw, sweaty, large hands, headaches (vascular), snoring/sleep apnoea, local pituitary affects-visual fields, hypopituitarism

What are some associated conditions of acromegaly?

HT, cardiac failure, sleep apnoea, DM, early CV death, colonic polyps and colon cancer

How is acromegaly diagnosed?

IGF1-sex/age matched, GTT-suppresion test: normal result-GH suppresses to 1ug/l after glucose

What tests apart from IGF1 and GTT can be used in acromegaly diagnosis?

Visual field, CT/MRI pituitary scan, Pituitary function tests

What is the treatment for acromegaly?

Pituitary surgery, external radiotherapy to pit fossa, retest GTT, if normal fine, if >1ug/l drug therapy:SSA- octreotide. Dopamine agonist e.g. cabergoline. GH receptor antagonist: pegvisomant

What is the efficacy of somatostatin analogues in acromegaly?

Reduces GH in most patients

What tumour shrinkage occurs due to somatostatin analogues in acromegaly?

30-50% decrease in size, takes 6-12/12, re expansion 6 weeks after stopping

What do somatostatin analogues provide pre-operatively?

Relieves headaches in 1hr, improved outcome

What are some S/Es of somatostatin analogues?

Local stinging, short term-flatulence, diarrhoea, abdominal pains, long term-gastritis, gallstones

What is the efficacy of dopamine agonists in acromegaly?

Can work well in moderately elevated GH

What is the last line in acromegaly therapy?

GH antagonist- pegvisomant

What do GH antagonists do to tumour size, IGF1 and serum GH concentrations?

Size does not decrease, occasional increase. IGF1 decreases but serum GH may increase

What follow up is needed in acromegaly?

Achieve clinically safe levels of GH and IGF1, check other pituitary hormones, cancer surveillance-colon and tubulo-villous adenoma, CV risk factors-bp, lipids, glucose, check for sleep apnoea

What is the anterior pituitary derived from?

Rathke's pouch

What is the anterior pituitary made up of histologically?

Islands-cords of cells, acidophils, basophils, chromophobe

What do somatrophs produce?

What do mammotrophs produce?

PRL

What do corticotrophs produce?

ACTH

What do thyrotrophs produce?

TSH

What do gonadotrophs produce?

FSH/LH

What cells are acidophils?

Somatotrophs, mammotrophs

What cells are basophils?

Cortico/thyro/gonadotrophs

What is the posterior pituitary made up of?

Non-myelinated axons of neurosecretory neurons

What can cause ant pit hyperfunction?

Adenoma, carcinoma

What can cause ant pit hypofunction?

Surgery, radiation, sudden haemorrhage into gland, ischaemic necrosis, tumour extending into sella, inflammatory conditions

In pituitary adenomas what can infarction lead too?

Panhypopituitarism

What are some functional pituitary adenomas?

Prolactinoma, GH secreting, ACTH secreting

What is the most common functional tumour?

Prolactinoma (30%)

What are some signs of prolactinoma?

Infertility, lack of libido, amenorrhea (25%)

What can a GH secreting adenoma cause an increase in?

Insulin like growth factors (IGF)

What does a GH Secreting adenoma stimulate?

Growth of bone, cartilage and connective tissue

What disease can be caused by an ACTH secreting adenoma?

Cushings

What kind of adenoma is a ACTH secreting tumour usually?

Microadenoma

What are some causes of pituitary hypofunction?

Primary/metastatic causes, trauma, subarachnoid haemorrhage, surgery or radiation, granulomatous inflammation, infarction/haemorrhage, hypothalamic lesions

What is a craniopharyngioma derived from?

Remnants of Rathke's pouch

Where does craniopharyngioma arise from?

Mostly suprasellar, some sella

What type of incidence does a craniopharyngioma have?

Bimodal-5-15yo, 6th to 7th decades

What symptoms and signs may a craniopharyngioma cause?

Headaches, visual disturbances, children may have growth retardation

What is the prognosis for craniopharyngioma?

Good, especially if tumour can be completely removed by surgery/radiation

Pituitary Flashcards

(77 cards)