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5 Endocrinology
Steroid use Advise wearing a bracelet declaring steroid use. Add 5– 10mg hydro-
https://t.me/med1917
cortisone to daily intake before strenuous activity/ exercise. Double steroids in febrile illness, injury, or stress. Give out syringes and in- date
show how to inject
admit for
Follow- up Yearly (BP,
100
IV
fluids if dehydrated).
mg IM if vomiting prevents oral intake (seek medical help;
U&E
); watch for autoimmune diseases (pernicious anaemia).
IM
hydrocortisone, and
Prognosis (treated) Adrenal crises and infections do cause excess deaths:
65
mean age at death for men is ~
3
yrs).
lose ~
yrs (11yrs <estimated life expectancy; women
Exogenous steroid use
Replacement steroids are vital in those taking long- term steroids when acutely
unwell. Adrenal insuciency may develop with deadly hypovolaemic shock, if
additional steroid is not given.
Steroid use Warn against abruptly stopping steroids. Emphasize that prescribing
doctors/ dentists/ surgeons must know of steroid use: give steroid card (
www.endocr inol ogy.org/ adre nal- cri sis
See p
).
819
.
https://
Excerpt from the notes of Miss E.L.R., 92 days before her death from
undiagnosed Addison’s disease. From the Coroner’s Court . . .
‘Typical day— wakes up at 11.30, still feels tired, then will have some breakfast and
1
usually fall asleep on the couch. The most energy req. activity in last
month is—
cooking herself a pasta meal. Then, totally exhausted will sleep more in pm, then
11
eat some dinner. Goes to bed at
45
kg. Now weighs 42kg.’
weigh
Placed on a page about Addison’s disease, we might think there are sucient
clues to raise the suspicion of Addison’s (even though her electrolytes were not
pm— latest. Not able to concentrate... Used to
19
particularly awry, and her pigmentation was barely perceptible). But change the
context to our last busy clinic. We are a little distracted. The memory of Addison’s
is fading. Who among us will hear the alarm bell ring?
221
3
3
Autoimmune polyglandular syndromes types 1– 4: 1 Monogenic syndrome (
signs: candidiasis, hypoparathyroidism + Addison’s.
immune thyroid disease ±
conditions but not Addison’s.
DM
± pleuritis/ pericarditis. 3 Autoimmune thyroid disease + other autoimmune
4
Autoimmune combinations not included in 1– 3.
AIRE
2
(Schmidt syndrome.) Adrenal insuciency + auto-
gene on chromosome 21);
5 Endocrinology
Hyperaldosteronism
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222
Primary hyperaldosteronism Excess production of aldosterone, independent of
the renin– angiotensin system, causing sodium and water retention, and renin release. Consider if: hypertension, hypokalaemia, or alkalosis in someone not on diuretics. Commonest cause of secondary hypertension.
Symptoms Often asymptomatic or signs of hypokalaemia (p
quadriparesis), cramps, paraesthesiae, polyuria, polydipsia.
Causes ~1/ 3 due to a solitary aldosterone- producing adenoma (some are linked to mu-
tations in K
plasia. Rare causes: adrenal carcinoma; or glucocorticoid- remediable aldosteronism
(
terone synthase gene, aldosterone production, & bringing it under the control of
GRA)
+
channels)4— Conn’s syndrome. ~2/ 3 due to bilateral adrenocortical hyper-
— the
ACTH
regulatory element of the 11- hydroxylase gene fuses to the aldos-
Te st s Initial screening test with
firmatory saline infusion test, imaging of adrenals and adrenal vein sampling. Do not
rely on a low K
history of early hypertension), genetic testing is available.
+
, as >20% are normokalaemic. For
aroscopic adrenalectomy is treatment of choice. Medical therapy with mineralocorticoid receptor antagonists (spironolactone) is an option for bilateral hyperplasia,
or those with Conn's who are unfit for surgery or express preference for medical
mgmt. Other drugs include amiloride.
normalizes biochemistry but not always
alternative.
•Adrenal carcinoma: surgery ± post- operative adrenolytic therapy with
mitotane— prognosis is poor.
Secondary hyperaldosteronism Due to a high renin from renal perfusion, eg
in renal artery stenosis, accelerated hypertension, diuretics,
Bartter’s syndrome This is a major cause of congenital (autosomal recessive)
salt wasting— via a sodium and chloride leak in the loop of Henle via mutations in
channels and transporters. Presents in childhood with failure to thrive, polyuria, and
polydipsia.
aldosterone production, leading to hypokalaemia and metabolic alkalosis, urinary
K
BP
is normal. Sodium loss leads to volume depletion, causing renin and
+
and Cl−. Tre at me nt K+ replacement,
Phaeochromocytoma
Rare catecholamine- producing tumours. They arise from sympathetic paraganglia
cells (= phaeochrome bodies), which are collections of chroman cells. They are
usually found within the adrenal medulla. Extra- adrenal tumours (paragangliomas)
are rarer, and often found by the aortic bifurcation (the organs of Zuckerkandl).
Tra di ti on al ly, ph ae oc hr om oc yt om as we re ro ug hl y t ho ug ht to fo ll ow th e
10
% malignant, 10% are extra- adrenal, 10% bilateral. Historically, it was also
rule:
thought that
mutations. Thus, family history is crucial and referral for genetic screening (particularly <
Associations ~70% are sporadic; 30% are part of hereditary cancer syndromes
p
209
(
ciated with mutations in succinate dehydrogenase (
Classic triad Episodic headache, sweating, and tachycardia (± , , or BP, see
‘Features of phaeochromocytoma’).
Te st s • Biochemical: plasma free metanephrines is first line. 24h urine for
metanephrines/ metadrenaline is an alternative if unavailable.
dominal
scan (can find extra- adrenal tumours, p
phenoxybenzamine or doxazosin (- blockers) is used before - blocker to avoid crisis
from unopposed - adrenergic stimulation, - block too if heart disease or tachycardic.
Consult the anaesthetist.
BP
(risk of BP). Emergency p
radio labelled
sent late, genetic screening.
10
% were familial— but it is now thought that ~30% are due to genetic
50
years old). A dangerous but treatable cause of hypertension (in <0.1%).
), eg
MEN- 2A
and 2B, neurofibromatosis, von Hippel– Lindau syndrome, and asso-
CT/ MRI,
or meta- iodobenzylguanidine (
MIBG
may be used. Foll ow- up Lifelong: malignant recurrence may pre-
666
): weakness (even
BP
but not always.
U&E,
renin:aldosterone ratio. If positive, consider con-
GRA
(suspect if there is a family
ACTH
Tre at me nt •Conn’s: lap-
•
GRA
: dexamethasone 1mg/ 24h PO for 4wks,
BP
. If BP is still , use spironolactone as an
CCF
, or hepatic failure.
NSAID
S (to inhibit prostaglandins), and
SDH
).
ACE
10
- i.
%
BOX
• Localization: ab-
MIBG
722
). Tre at me nt Surgery - blockade pre- op:
Post- op Do 24h urine metanephrine 2wks post- op, monitor
820
. If malignant, chemotherapy or therapeutic
; chroman- seeking isotope)
.
5 Endocrinology
GFR
GA
Hypertension: a common context for hyperaldosteronism tests
CNS
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Think of Conn’s in these contexts:
• Hypertension associated with hypokalaemia.
• Refractory hypertension, eg despite ≥3 antihypertensive drugs.
• Hypertension occurring before 40yrs of age (especially in women).
The approach to investigation remains controversial, but the simplest is to look
for a suppressed renin and aldosterone (may be normal if there is severe hypokalaemia). This is followed by a confirmatory saline infusion test, prior to proceeding
with imaging. A
This should be done after hyperaldosteronism is proven, due to the high number
CT
or
MRI
of the adrenals is then performed to localize the cause.
of adrenal incidentalomas. If imaging shows a unilateral adenoma, adrenal vein
sampling may be done (venous blood is sampled from both adrenals). If one side
reveals increased aldosterone:cortisol ratio compared with the other (>
ference), an adenoma is likely, and surgical excision is indicated. If no nodules or
bilateral nodules are seen, think about adrenal hyperplasia or
NB:
ren al ar tery sten osis is a more c omm on ca use o f refr acto ry BP an d K+ (p
GRA
3
- fold dif-
.
Features of phaeochromocytoma (often episodic and often vague)
Try t o d ia gn os e b ef or e d ea th : s us pe ct i f BP ha rd to c ontr ol, a ccel erat ing, or ep isod ic.
• Heart Pulse; palpitations/ VT; dyspnoea; faints; angina; MI/
•
Headache; visual disorder; dizziness; tremor; numbness; fits; encephalopathy;
Horner’s syndrome (paraganglioma); subarachnoid/
• Psychologi cal A nxiety; panic; hy peract ivity; confu sion; episodic p sychos is.
• Gut
D&V
; abdominal pain over tumour site; mass; mesenteric vasoconstriction.
• Others Sweats / flushes; heat intolerance; pallor; T°; backache; haemoptysis.
Symptoms may be precipitated by straining, exercise, stress, abdominal pressure,
surgery, or by agents such as - blockers,
the tricyclics. The site of the tumour may determine precipitants, eg if pelvic,
IV
contrast agents, metoclopramide, or
LVF
CNS
hae morrhage.
; cardiomyopathy.
precipitants include sexual intercourse, parturition, defecation, and micturition.
Adrenergic crises may last minutes to days. Suddenly patients feel ‘as if about
to die’— and then get better, or go on to develop a stroke or cardiogenic shock.
On examination, there may be no signs, or hypertension ± signs of heart failure/
cardiomyopathy (± paradoxical shock, similar to Takotsubo’s
roid swelling, glycosuria during attacks, or terminal haematuria from a bladder
6
), episodic thy-
phaeochromocytoma.
223
311
).
5
4
Tumours from the zona glomerulosa, zona fasciculata, or zona reticularis associate with syndromes of
mineralocorticoids, glucocorticoids, or androgens respectively, usually; remember ‘
5
Takotsubo cardiomyopathy (= stress- or catecholamine- induced cardiomyopathy/ broken heart syndrome) may cause sudden chest pain mimicking
on echo (also ejection fraction) occurring during catecholamine surges. It is a cause of
normal arteries. The stress may be medical (
≈ miner
MI
, with ST segments, and its signature apical ballooning
SAH,
p
474
) or psychological.
MI
’
.
in the presence of
5 Endocrinology
Hirsutism, virilism, gynaecomastia, and impotence
PCOS
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224
Hirsutism Co mmon (10% of women) and usually benign. It implies male pattern hair
growth in women. Causes are familial, idiopathic, or are due to androgen secretion
by the ovary (eg polyc ystic ovar ian sy ndrome, ovarian cance r,
gland (eg non- classic congenital adrenal hyperplasia,
adrenal cancer), or drugs (eg steroids).
Polycystic ovarian syndrome (
OHCS
OHCS
p
115
, Cushing’s syndrome,
p
secondary oligo- or amenorrhoea, infertility, obesity, acne, and hirsutism (
Ultrasound: bilateral polycystic ovaries. Blood tests: testosterone (if
look for an androgen- producing adrenal or ovarian tumour), sex- hormone binding
LH:FSH
globulin,
conformity to society’s perceived norms of feminine beauty.
ratio (not consistent),
TSH
, lipids. Address any feelings of lack of
Management Healthy
eating, optimize weight, shaving; laser photoepilation; wax; creams, eg eflornithine,
or electrolysis (expensive/ time- consuming, but eective).
• Oestrogens: combined contraceptive pill (
line. Yasmin® and co-cyprindiol contain progestins with lower androgenicity
(desogestrel and cyproterone) but may have higher rate of
Stop co- cyprindiol
of increased
refer the woman to secondary care for specialist treatment.
• Metformin (helps with insulin resistance) and spironolactone are sometimes tried.
• Clomifene is used for infertility (a fertility expert should prescribe).
3– 4
months after hirsutism has completely resolved because
VTE
risk. If
COC
S are contraindicated or have not worked (after
OHCS
p
152
)— third- generation are first
VTE
so use second line.
Virilism Onset of amenorrhoea, clitoromegaly, deep voice, temporal hair recession +
hirsutism. Look for an androgen- secreting adrenal or ovarian tumour.
Gynaecomastia (Ie abnormal amount of breast tissue in men; may occur in normal
puberty.) Oestrogen/ androgen ratio (vs galactorrhoea in which prolactin is ).
Causes Hypogonadism (see
BOX
‘Male hypogonadism’), liver cirrhosis (oestrogens),
hyperthyroidism, tumours (oestrogen- producing, eg testicular, adrenal; human
chorionic gonadotropin- producing, eg testicular, bronchial); drugs: oestrogens, spironolactone, digoxin, testosterone, marijuana; if stopping is impossible, consider testosterone if hypogonadism ± anti- oestrogen (tamoxifen).
Erectile dysfunction Erections result from neuronal release of nitric oxide (NO)
which, via c
GMP
smooth muscle cells, allowing engorgement. Common after
2
+
and Ca
, hyperpolarizes and thus relaxes vascular and trabecular
50
yrs, and often multifactorial. A psychological facet is common (esp. if erectile dysfunction occurs only
in some situations, if onset coincides with stress, and if early morning erections
still occur: these also persist in early organic disease).
three: smoking, alcohol, and diabetes (reduce
endocrine: hypogonadism, hyperthyroidism, prolactin; neurological: cord lesions,
MS
, autonomic neuropathy; pelvic surgery: eg bladder- neck, prostate; radiotherapy;
atheroma; renal or hepatic failure; prostatic hyperplasia; penile anomalies: eg post-
priapism, or Peyronie’s (
antidepressants, oestrogens, finasteride, narcotics.
psychological history do:
fasting testosterone ± prolactin. Other specialized tests such as Doppler rarely re-
• Treat causes. • Counselling. • Oral phosphodiesterase (
quired.
GMP
. Erection isn’t automatic (depends on erotic stimuli). Sildenafil 25–
c
1
h pre- sex (food and alcohol upset absorption). SE Headache (16%); flushing
½–
10
%); dyspepsia (7%); stuy nose (4%); transient blue- green tingeing of vision
(
(inhibition of retinal
tors’. Tadalafil (long t½,)
(
5– 20
mg). • Vacuum aids (ideal for penile rehabilitation after radical prostatec-
p
694
); drugs: digoxin, - blockers, diuretics, antipsychotics,
U&E, LFT
, fasting glucose, HbA1c,
PDE6).
CI See
BOX
10– 20
‘Contraindications and cautions to PD5
mg ½– 36h pre- sex. Don’t use > once daily. Vardenafil
tomy), intracavernosal injections, transurethral pellets, and prostheses (inflatable or
malleable; partners may receive unnatural sensations).
engineering (eg on acellular collagen scaolds) is in its infancy.
Organic causes The big
NO
+ autonomic neuropathy). Also
Workup After a full sexual and
TFT, LH, FSH
• Corpus cavernosum tissue
174
), the adrenal
OHCS
≥
5
, lipids,
PDE5
) inhibitors
) causes
p
116
nmol/ L,
6/ 12
9AM
100
mg
inhibi-
).
),
5 Endocrinology
Contraindications and cautions to
CI
https://t.me/med1917
PD
inhibitors
5
Contraindications
• Concurrent use of nitrates.
• BP high or systolic <90mmHg/ arrhythmia.
• Degenerative retinal disorders, eg retinitis pigmentosa.
• Unstable angina/ stroke <6 months ago.
• Myocardial infarction <90 days ago.
Cautions Angina (especially if during intercourse).
• Bleeding; peptic ulcer (sildenafil).
• Marked hepatic or renal impairment.
• Peyronie’s disease or cavernosal fibrosis.
• Risk of priapism (sickle cell anaemia, myeloma, leukaemia).
• Concurrent complex antihypertensive regimens.
• Dyspnoea on minimal eort (sexual activity may be unsupportable).
Use in coronary artery disease has been a question, but is probably
Interactions Nitrates (contraindication); cytochrome
OK
P450 (CYP3A
.
20
) inducers:
macrolides, protease inhibitors, theophyllines, azole antifungals, rifampicin, phenytoin, carbamazepine, phenobarbital, grapefruit juice (bioavailability). Caution if
- blocker use; avoid vardenafil with type
3
ant i- arrhythmics (sotalol; amiodarone)— as well as nitrates as above- mentioned.
1A
(eg quinidine; procainamide) and type
Male hypogonadism
Hypogonadism is failure of testes to produce testosterone, sperm, or both.
Fea ture s: s mall te stes , libido, erectile dysfunction, loss of pubic hair, muscle bulk,
fat, gynaecomastia, osteoporosis, mood. If prepubertal: virilization; incomplete
puberty; eunuchoid body; reduced secondary sex characteristics. Causes include:
Primary hypogonadism Due to testicular failure, eg from: • Local trauma, tor-
sion, chemotherapy/ irradiation.
• Renal failure, liver cirrhosis, or alcohol excess (toxic to Leydig cells). •
rosy.
Chromosomal abnormalities, eg Klinefelter’s syndrome (
development, small testes, and gynaecomastia. Anorchia is rare.
Secondary hypogonadism Gonadotropins (
pituitarism.
releasing hormone deficiency, often with anosmia and colour blindness.
Systemic illness (eg
dromes (
(p
• Prolactinoma. • Kallman’s syndrome— isolated gonadotropin-
p
852
COPD; HIV; DM
& p
OHCS
226
) If total testosterone 8nmol/ L, on 2 mornings (or <15 if LH too) and
muscle bulk, testosterone may help, eg
• Post- orchitis, eg mumps,
LH & FSH
). • Laure nce– Moon– Biedl and Prader– Willi syn-
856
). • Age.
1
% dermal gel (Testogel®). Heart,
HIV,
brucellosis, lep-
47XXY
)— delayed sexual
), eg from: • Hypo-
bladder, and sexual function may perk up in age- related hypogonadism. Beware
medicalizing ageing!
Severe
CKD
; polycythaemia; prostate, breast, or liver ca. Monitor
PSA
and Hct.
225
•
5 Endocrinology
Hypopituitarism
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226
Hypopituitarism entails secretion of anterior pituitary hormones and/ or posterior
figs
5.3
, p
199, 5.22
pituitary hormones (
GH
), gonadotropins: follicle- stimulating hormone (
mone (
LH
), thyroid- stimulating hormone (
mone (
ACTH
(
), prolactin (
PRL
). Panhypopituitarism is deficiency of all anterior hormones,
). They are aected in this order: growth hor-
FSH
TSH
), and adrenocorticotrophic hormone
) and luteinizing hor-
usually caused by irradiation, surgery, or pituitary tumour.
Causes are at three levels. 1 Hypothalamus Kallman’s syndrome (p
TB)
flammation, infection (meningitis,
tumour (craniopharyngioma,
3
Pituitary Tumour, irradiation, inflammation, autoimmunity,6 infiltration
mation.
(haemochromatosis, amyloid, metastases), ischaemia (pituitary apoplexy,
Sheehan’s syndrome
8
).
, ischaemia. 2 Pituitary stalk Trauma, surgery,
p
228
), meningioma, carotid artery aneurysm, inflam-
Features Due to:
1
Hormone lack •GH: central obesity, atherosclerosis, dry wrinkly skin, strength,
balance, wellbeing, exercise ability, cardiac output, osteoporosis, glucose.
•Gonadotropin (
porosis, breast atrophy, dyspareunia.
hypogonadism (hair, all over; small testes; ejaculate volume; spermatogenesis).
•Thyroid: as for hypothyroidism (p
p
220
(
2
Causes Eg pituitary tumour (p
FSH; LH
): : oligomenorrhoea or amenorrhoea, fertility, libido, osteo-
).
NB:
no skin pigmentation as
: erectile dysfunction, libido, muscle bulk,
214
). •Corticotropin: as for adrenal insuciency
ACTH
. •Prolactin: rare: absent lactation.
228
), causing mass eect, or hormone secretion
with secretion of other hormones— eg prolactinoma, acromegaly, rarely Cushing’s.
Tests (The triple stimulation test is now rarely done.)
• Basal tests LH and
prolactin (may be , from loss of hypothalamic dopamine that normally inhibits its
release), insulin- like growth factorcortisol (). Also do
• Dynamic tests 1 Short Synacthen® test: (p
2
Insulin tolerance test (
GH
axes. CI: epilepsy, heart disease, adrenal failure. Consult lab first. It involves IV
insulin to induce hypoglycaemia, causing stress to cortisol and
done in the morning (water only taken from
cose and hydrocortisone to hand and
and the patient should become symptomatic when cortisol and
GH
Normal:
3
Arginine + growth hormone- releasing hormone test.
4
Glucagon stimulation test is alternative when
• Investigate cause
FSH
( or ), testosterone or oestradiol ();
U&E
(Na+ from dilution), Hb (normochromic, normocytic).
ITT
): done in specialist centres to assess the adrenal and
>20mU/ L & peak cortisol >
MRI
scan to look for a hypothalamic or pituitary lesion.
TSH
1
(
IGF- 1
; — used as a measure of GH axis, p
220
) to assess the adrenal axis.
22:00
IV
h the night before). Have 50% glu-
access. Glucose must fall below 2.2mmol/ L
550
nmol/ L (exact threshold varies locally).
ITT
is contraindicated.
GH
Treatment Refer to an endocrinologist for assessment of pituitary function and to
oversee hormone replacement and treatment of underlying cause.
• Hydrocortisone for 2° adrenal failure (p
Risk of precipitation of adrenal crisis if thyroxine given before hydrocortisone.
• Thyroxine if hypothyroid (p
• Hypogonadism (for symptoms and to prevent osteoporosis). : options include
topical testosterone gels (eg Testogel®), or testosterone undecanoate
12
weeks. : (premenopausal). Hormone replacement therapy: transdermal
every
oestradiol patches, or oral
214
HRT
220
) before other hormones are given.
, but
TSH
is useless for monitoring).
(this needs a progestogenic component in women
with intact uterus) ± testosterone or dehydroepiandrosterone (
androgenic women; a small amount may improve wellbeing and sexual function,
and help bone mineral density and lean body mass).
• Gonadotropin therapy is needed to induce fertility in both men and women.
• Growth hormone (GH). Somatotrophin mimics human GH. It addresses problems
of fat mass, bone mass, lean body mass (muscle bulk), exercise capacity, and
problems with heat intolerance.
225
), tumour, in-
p
228
;
( or ),
T
secretion. It is
GH
are taken.
1000
mg IM
DHEA
, in hypo-
DIC
();
4
232),
7
;
5 Endocrinology
Fig 5.
https://t.me/med1917
22
Neuroendocrinology: emotions
Creation of Adam) ‘all gods and demons that have ever existed are within us as possibilities, desires, and ways of escape’. Within the dark red vault of our skull we see human and god- like forms
reaching out, as thoughts escape into actions— with legs extending into our brainstem (b) and
a fist is pushing from our hypothalamus into the pituitary stalk (p). Above the pituitary we have
thoughts, ideas, impulses, and neurotransmitters. Below we have hormones. Between is the realm
of neuroendocrinology— the neurosecretory cells which turn emotions into the releasing factors
for the pituitary hormones (
fig
5.4
, p
199
).
Image courtesy of Gary Bevans; quote from Frank Lynn Meshberger.
thoughts
actions. As Michelangelo foretold (in his
Michelangelo, Renaissance Man of the Brain, Too?
227
6
Autoimmune hypophysitis (= inflamed pituitary) mimics pituitary adenoma. It may be triggered by preg-
nancy or immunotherapy blocking
7
Snake bite is a common cause in India (eg when associated with acute kidney injury).
8
Sheehan’s syndrome is pituitary necrosis after postpartum haemorrhage.
CTLA- 4
and
PD- 1
. No pituitary autoantigen is yet used diagnostically.
5 Endocrinology
Pituitary tumours
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228
Pituitary tumours (almost a lways benign adenomas) account for 10% of intracranial tu-
figs
5.23, 5.24
mours (
across, and a macroadenoma is >
1
Chromophobe 70%. Many are non- secretory,9 some cause hypopituitarism. Half
produce prolactin (
2
Acidophil 15%. Secrete GH or
3
Basophil 15%. Secrete
). They may be divided by size: a microadenoma is a tumour <1cm
Symptoms are caused by pressure, hormones (eg galactorrhoea), or hypopituitarism
p
226
).
FSH-
(
secreting tumours can cause macro- orchidism in men, but are rare.
Fea ture s of loc al p res sur e Headache, visual field defects (bitemporal hemianopia, due
to compression of the optic chiasm), palsy of cranial nerves
of the cavernous sinus;
hypothalamic disease or post- pituitary surgery); disturbance of hypothalamic centres of
T
°, sleep, and appetite; erosion through floor of sella leading to
Te st s
MRI
defines intra- and supra- sellar extension; accurate assessment of visual
fields; screening tests:
short Synacthen® test.
p
219
. Urine/ serum osmolality ± water depri vation test if DI is s uspec ted (p
Treatment Start hormone replacement as needed (p
before levothyroxine, as thyroxine may precipitate an adrenal crisis. For Cushing’s
disease see
• Surgery (fig
p
219
, prolactinoma p
5.26
) Most pituitary surgery is trans- sphenoidal, but if there is suprasellar extension, a trans- frontal approach may be used. For prolactinoma,
treatment is medical with a dopamine agonist,
100
mg IV/ IM. Subsequent cortisol replacement and reassessment varies with local
protocols: get advice. Post- op: retest pituitary function (
ment needs. Repeating dynamic tests for adrenal function
• Radiotherapy (Eg stereotactic.) Good for residual or recurrent adenomas (good
rates of tumour control and normalization of excess hormone secretion).
Post- op Re cur ren ce may occ ur lat e af te r su rge ry, so l on g- term follow- up is required.
Fer tili ty sh ould be d iscuss ed: this may b e re duce d pos t- op due to gonadotropins.
Pituitary apoplexy Infarction of the pituitary gland due to either haemorrhage
or ischaemia. Suspect if acute- onset headache, meningism,
visual field defect, especially if there is a known tumour (may present like subarachnoid haemorrhage). Apoplexy is a medical emergency— as prompt administration
of steroids may be life- saving.
a pituitary multidisciplinary team; if marked neuro- ophthalmic signs, early surgery
8
days) is usually indicated.
(within
Craniopharyngioma Not strictly a pituitary tumour: it originates from Rathke’s
pouch so is situated between the pituitary and
are the commonest childhood intracranial tumour. Over
with growth failure; adults may present with amenorrhoea, libido, hypothalamic
symptoms (eg
MRI
(calcification in 50%, may also be seen on skull x- ray). Treatment Surgery ±
DI
, hyperphagia, sleep disturbance) or tumour mass eect. Tests CT/
post- op radiation; test pituitary function post- op.
Table 5.
5
Freq uen cy o f ho rm one s se cre ted by p itu ita ry a den om as b ase d on imm uno his toc he mis try
Hormone % Hormone %
PRL
only (prolactinoma)
GH
only (acromegaly)
PRL
and
GH
* Sensitive methods of
now more frequently found at microadenoma stage, medially located, and without associated hormone
hypersecretion. In these tumours, somatostatin analogues (
Eur J Endocrinol.
9
If <1cm, usually ‘incidentaloma’; most non- functioning macroadenomas are revealed by mass eect and/
or hypopituitarism. Here, recurrence after surgery is common, so follow carefully with
TSH
2003;148:433– 42
1
cm. There are three histological types (table
PRL
); a few produce
ACTH
. Local pressure eect rare.
fig
5.25
). Also, diabetes insipidus (DI) (p
PRL, IGF- 1
(p
OGTT
if acro meg aly s usp ecte d (p
ACTH
or GH. Local pressure eect in 30%.
. Local pressure eect in 10%.
ACTH, 9AM
co rti sol,
232
PRL
),
232
226
230
, acromegaly p
232
.
p
230
. Pre- op: ensure hydrocortisone
Urgent steroids (hydrocortisone
3
rd ventricle floor. They are rare, but
35
%
ACTH
20
%
7
%
measurement have improved recognition of
.
(Cushing’s disease)7%
LH/ FSH/ TSH
No obvious hormone
p
232
) are very helpful. See also Socin et al.,
5.5
):
III, IV, VI
(pressure or invasion
234
; more likely from
CSF
rhi norrh oea.
TFT
S,
LH/ FSH
, testosterone in ,
). If Cushing’s suspected, see
234
).
). Ensure steroids are given
1
st- line
p
226
) to assess replace-
≥
6
weeks post- op.
21
GCS
, ophthalmoplegia/
100
mg IV); involve
50
% present in childhood
*
≥1%
30
MRI
%
S.
TSH
- secreting tumours. These are
5 Endocrinology
Fig 5.
Supraoptic recess
III
Internal cartoid
Sphenoid bone
Sphenoid sinus
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23
Coronal T1- weighted
(no gadolinium contrast) showing a lesion in the
pituitary fossa, most likely a haemorrhagic pituitary adenoma. Dierential diagnosis includes a
Rathke’s cleft cyst.
Courtesy of Norwich Radiology Dept.
MRI
of the brain
Fig 5.
24
Sagittal T1- weighted
(no gadolinium contrast) showing a lesion in the
pituitary fossa (see
Courtesy of Norwich Radiology Dept.
fig
5.23
).
MRI
of the brain
229
Suprasellar cistern
IV
V
1
V
2
VI
Fig 5.
25
The pituitary gland’s relationships to cranial nerves
Endoscope
Fig 5.
26
Endoscopic surgery is now possible for pituitary surgery.
Hypothalamus
Optic chiasm
Pituitary stalk
Pituitary gland
Temporal lobe
artery
Sphenoid sinus
III, IV, V
, and VI.
Pituitary adenoma
5 Endocrinology
Hyperprolactinaemia
https://t.me/med1917
230
This is the commonest hormonal disturbance of the pituitary. It presents earlier
in women (menstrual disturbance) but later in men (eg with erectile dysfunction
and/ or mass eects). Prolactin stimulates lactation.
gonadism, infertility, and osteoporosis, by inhibiting secretion of gonadotropinreleasing hormone (hence
Causes of raised plasma prolactin
release is inhibited by dopamine produced in the hypothalamus. Hyperprolactinaemia
may result from:
2
Disinhibition, by compression of the pituitary stalk, reducing local dopamine levels.
3
Use of a dopamine antagonist. A
5000
is likely to be due to a prolactinoma, with macroadenomas (>10mm) having the
>
highest levels, eg
• Physiological Pregnancy; breastfeeding; stress. Acute rises occur post- orgasm.
• Drugs (most common cause) Metoclopramide; haloperidol; methyldopa; oes-
10 000– 100 000
trogens; ecstasy/
hyperprolactinaemia may cause libido, anorgasmia, and erectile dysfunction).
• Diseases Prolactinoma: micro- or macroadenoma. Stalk damage: pituitary aden-
omas, surgery, trauma. Hypothalamic disease: craniopharyngioma, other tumours.
Other: hypothyroidism (due to
LH/ FSH
and testosterone or oestrogen).
PRL
is secreted from the anterior pituitary and
1
Excess production from the pituitary, eg prolactinoma.
PRL
of
.
MDMA
;11 antipsychotics (a reason for ‘non- compliance’: sustained
TRH
), chronic renal failure (excretion).
10,11
Raised levels lead to hypo-
1000– 5000
mU/ L may result from any, but
Symptoms Amenorrhoea or oligomenorrhoea; infertility; galactorrhoea
fig
5.27
). Also: libido, weight, dry vagina. Erectile dysfunction, facial hair, gal-
(
actorrhoea. May present late with osteoporosis or local pressure eects from the
p
228
tumour (
Tests Basal
nancy test,
).
PRL
: non- stressful venepuncture between 09.00 and 16.00h. Do a preg-
TFT, U&E. MRI
pituitary if other causes are ruled out.
Management Refer to a specialist endocrinology clinic. Dopamine agonists
1
(bromocriptine or cabergoline) are
Microprolactinomas A tumour <10mm on
microprolactinomas). Cabergoline, a dopamine agonist,
strual cycles and tumour size. The initial dose is
SE:
a week.
or rarely, impulse- control disorders. If pregnancy is planned, use barrier contraception until
after the
nausea, depression, postural hypotension (minimize by giving at night),
2
periods have occurred. If subsequent pregnancy occurs, stop cabergoline
1
st missed period. An alternative dopamine agonist is bromocriptine: less
eective but better safety data in pregnancy.
st line.
MRI
(~25% of us have asymptomatic
PRL
0.25
NB
: ergot alkaloids (bromocriptine and
secretion, restores men-
mg twice a week or 0.5mg once
cabergoline) can cause fibrosis (eg echocardiograms are needed). Trans- sphenoidal
surgery may be considered if intolerant of dopamine agonists. It has a high success
rate, b ut there are risks of permane nt hormone deficiency a nd prolac tinoma recurrence, and so it is usually reserved as a
Macroprolactinomas A tumour >10mm diameter on
2
nd- line treatment.
MRI
. As they are near the
optic chiasm, there may be acuity, diplopia, ophthalmoplegia, visual- field loss, and
optic atrophy. Treat initially with a dopamine agonist (cabergoline if fertility is the
goal). Surgery is rarely needed, but consider if visual symptoms or pressure effects which fail to respond to medical treatment. Cabergoline, and in some cases
radiation therapy, may be required post- op as complete surgical resection is uncommon. If pregnant, monitor closely ideally in a combined endocrine/ antenatal
clinic as there is risk of expansion.
Follow- up Monitor
Medication can be decreased after
PRL
. If headache or visual loss, check fields (? do
2
yrs, but recurrence of hyperprolactinaemia and
expansion of the tumour may occur, and so these patients should be monitored
carefully.
MRI)
10
.
10
The prolactin increase ( and ) after coitus is ~
prolactin is part of a feedback loop decreasing arousal by inhibiting central dopaminergic processes. The size
of post- orgasmic prolactin increase is a neurohormonal index of sexual satisfaction.
11
MDMA
also oxytocin; prolactin + oxytocin are thought to mediate post- orgasmic wellbeing.
400
% greater than after masturbation; post- orgasmic
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