Diabetes + pituitary Flashcards
Diabetes
1
Q
What is diabetes insipidus?
A
Inadequate secretion or insensitivity to vasopressin, causing hypotonic polyuria
2
Q
What is the vasopressin pathway?
A
ADH is created in the hypothalamus
ADH is secreted in the posterior pituitary
ADH binds to the kidney and increases water reabsorption
Urine osmolality is raised
Serum osmolality is decreased
3
Q
What are the two types of diabetes insipidus?
A
Cranial
Nephrogenic
4
Q
What are the causes of cranial DI?
A
Posterior pituitary fails to secrete ADH
Due to: pituitary tumour, infection, sarcoidosis
5
Q
What are the causes of nephrogenic DI?
A
Collecting ducts insensitive to ADH
Hypocalcaemia, hyperkalaemia, lithium, inherited (AVPV2 gene), idiopathic
6
Q
What is the presentation of DI?
A
Polyuria
Nocturia
Polydipsia
Lethargy/irritability/confusion (high Na)
7
Q
What are the investigations for DI?
A
U+E
Glucose
Water deprivation test
8
Q
What happens during water deprivation of a normal Pt?
A
Urine becomes concentrated
osm >600
9
Q
What happens during water deprivation of a Pt with cranial DI?
A
Kidneys are unable to concentrate the urine
osm <400
10
Q
What happens during water deprivation of a Pt with nephrogenic DI?
A
Kidneys are unable to concentrate the urine
osm <400
11
Q
What do you give a Pt for the second part of the water deprivation test?
A
Desmopressin
12
Q
What happens when you give desmopressin to a Pt with cranial DI?
A
Urine osm raises by >50% after desmopressin
13
Q
What happens during water deprivation of a Pt with nephrogenic DI?
A
Urine osm raises by <45% after desmopressin
14
Q
What is the management for DI?
A
Treat the cause eg.
Cranial- intranasal desmopressin
Nephrogenic- thiazide diuretic or NSAIDs
15
Q
What is T1DM?
A
Hyperglycaemia due to a deficiency of insulin production (90% autoimmune destruction of B cells)
16
Q
What is T2DM?
A
Hyperglycaemia due to a resistance to insulin action
17
Q
What is the presentation of T1DM?
A
Polydipsia
Polyuria
Tired/weight loss
DKA
18
Q
What are the clinical features of a DKA?
A
N+V
Kussmaul breathing
Ketone breath
Abdo pain
19
Q
What is the presentation of T2DM?
A
Polydipsia
Polyuria
20
Q
What are the risk factors for T1DM?
A
HLA DR3/4
Other autoimmune conditions
21
Q
What are the risk factors for T2DM?
A
Obesity FHx Ethnicity Endocrine Drugs
22
Q
How is diabetes mellitus diagnosed?
A
Blood glucose measurement
Fasting >= 7.0mmol/L
Random > 11.1mmol.L
23
Q
What is the management for T1DM?
A
Insulin
Patient education
24
Q
What is the management for DKA?
A
Fluids
25
What is the management for T2DM?
Diet and lifestyle
| Metformin/sulphonylurea/insulin
26
How can you categorise hyponatraemia?
Hypovolaemia
Euvolaemia
Hypervolaemia
27
What are the causes of hypovolaemic hyponatraemia?
Diarrhoea
Vomiting
Diuretics
28
What are the causes of euvolaemic hyponatraemia?
Hypothyroidism
Hypoadrenalism
SIADH (pneumonia, cancer)
29
What are the causes of hypervolaemic hyponatraemia?
HF
Cirrhosis
Nephrotic syndrome
30
What are the signs of hypovolaemic hyponatraemia?
Reduced turgor
Postural hypotension
Dry mucous membranes
31
What are the signs of hypervolaemic hyponatraemia?
Oedematous
| High JVP
32
What are the investigations for hypovolaemic hyponatraemia?
Urine sample
| -low Na as body tried to retain Na due to hypovolaemia
33
What are the investigations for euvolaemic hyponatraemia?
TFTs
synACTHen test
Drug review, breast exam, CXR, brain MRI
34
What should you do if a Pt is severely hyponatraemic?
Give slow hypertonic saline
35
What should you be careful for when giving a Pt hypertonic saline and why?
Do not exceed 10mmol/L in the first 24h
| Risk of central pontine myelinosis
36
What are the complications of hyponatraemia?
Seizures
| Decreased consciousness
37
What are the causes of hypernatraemia?
```
Vomiting
Diarrhoea
Burns
Diabetes insipidus
Primary hyperaldosteronism (Conn's)
```
38
What is the presentation of hyponatraemia?
MILD: nausea, vomiting, headache, anorexia and lethargy.
MODERATE: muscle cramps, weakness, confusion and ataxia.
SEVERE: drowsiness, seizures and coma.
39
What is the management for hypernatraemia?
Replace the water
40
What is SIADH?
Too much ADH, causing too much water reabsorption
Low serum Na, high urine osm, high urine Na
NB: SIADH is not a final diagnosis
41
What are the causes of SIADH?
`
Primary brain injury (e.g. meningitis. subarachnoid haemorrhage)
Malignancy (e.g. small-cell lung cancer)
Drugs (e.g. carbamazepine, SSRIs, amitriptyline)
Infectious (e.g. atypical pneumonia, cerebral abscess)
Hypothyroidism
42
What is the management for SIADH?
Treat the underlying cause
Fluid restrict to 0.5-1L
If ineffective, give demeclocycline/tolvaptan
43
What is the prolactin axis/pathway?
Hypothalamus -> TRH -> anterior pituitary
Anterior pituitary -> prolactin -> hypothalamus
Hypothalamus -> dopamine -> inhibits anterior pituitary
44
What are the causes of hyperprolactinaemia?
Pituitary prolactinoma
Hypothyroidism
Metoclopramide/antipsychotics
Pregnancy, breast feeding
45
What are the clinical features of female hyperprolactinaemia?
Galactorrhoea, amenorrhoea, infertility, loss of libido
| Headache, visual field loss
46
What are the clinical features of female hyperprolactinaemia?
Loss of libido, infertility
| Headache, visual field loss
47
What are the investigations for hyperprolactinaemia?
Prolactin
TFTs
Pituitary MRI
48
What is the management for hyperprolactinaemia?
```
DA agonist (bromocriptine/cabergoline)
Surgery
```
49
What is the thyroid axis/pathway?
Hypothalamus -> TRH -> anterior pituitary
Anterior pituitary -> TSH -> thyroid gland
Thyroid gland -> T3/4
T3/4 negative feedback to Hypothalamus + pituitary
50
Define hyperthyroidism + give the 2 aetiologies
Excess circulating T4/3 due to:
1. increased hormone synthesis (hyperthyroidism)
2. increased release of stored hormones (thyroiditis)
51
What are the signs and symptoms of hyperthyroidism?
```
Heat intolerance/sweating
Palpitations, irregular pulse
Irritable, restlessness
Weight loss, good appetite
Diarrhoea
Menstrual irregularity/impotence
Tremor, hyperreflexia
```
52
What are the signs and symptoms of hypothyroidism?
```
Cold intolerance
Bradycardia
Lethary
Weight gain
Constipation
Oligomenorrhoea
Dry skin/cold hands
Decreased reflexes, c arpel tunnel
```
53
What are the types of hyperthyroidism?
Grave's disease (80%)
De Quervain's thyroiditis
Toxic multinodular goitre
Adenoma
54
What is Grave's disease? Explain the pathophysiology
```
Autoimmune disease- antibodies to TSH receptors
TRAb bind to:
receptors on the thyroid
behind the eyes
the skin
Causes inflammation and draws water into the tissue --> Grave’s triad:
- exopthalmos
- thyroid acropachy
- pretibial myxoedema
```
55
What is Grave's triad?
Caused by a TRAb binding:
- Exophthalmos
- Pretibial myxoedema
- Thyroid acropachy= soft tissue swelling of the hands and feet, onycholysis, clubbing and periosteal growth.
56
Symptoms and signs of De Quervain's thyroiditis
Post-viral inflammation
3 transient stages:
1. hyperthyroidism (virus replicates in thyroid, pushes out T3/4)
2. hypothyroidism (as all the T3/4 has been released)
3. euthyroid- self-limiting
Painful goitre, fever, ↑ESR
57
Which 2 cohorts is multinodular goitre more common?
elderly
| iodine deficient areas
58
Define thyroid adenoma
Solitary nodule secreting T3/4
59
What will you see on a radioisotope scan of Grave's disease?
Diffuse increased iodine uptake
60
What will you see on a radioisotope scan of De Quervain's thyroiditis?
No iodine uptake
Thyroid stops producing thyroid hormones, just releases it
61
What will you see on a radioisotope scan of a toxic multinodular goitre?
MULTIPLE areas of increased iodine uptake
62
What will you see on a radioisotope scan of a thyroid adenoma?
SINGLE area of increased uptake
63
What are the causes of hypothyroidism?
```
Autoimmune Hasimoto's thyroiditis
Iodine deficiency
Iatrogenic (post-surgery, radioiodine, amiodarone)
De Quervain's thyroiditis
Congenital thyroid dysgenesis
```
64
What is the commonest cause of hypothyroidism in the West? What does it commonly present with?
Autoimmune Hasimoto's thyroiditis
other autoimmune diseases: T1DM, Addison's
65
What is the commonest cause of hypothyroidism in the worldwide?
Iodine deficiency
66
What is the management for hypothyroidism?
Levothyroxine 25-200 micrograms/day
more stable, synthetic T4 with longer t1/2 so easier to control
67
State an acute complication of hypothyroidism
myxoedema coma
Life-threatening presentation of hypothyroidism seen in patients with poorly controlled or undiagnosed hypothyroidism (eg elderly).
May also be precipitated by certain triggers (certain drugs, stroke, trauma, HF)
68
What is the presentation of a myxoedema coma?
Hypothermia
Confusion
Hypoventilation
Hyponatraemia
Heart failure
Coma
69
What is the treatment for a myxoedema coma?
IV thyroid replacement (liothyronine (T3/4) --> levothyroxine (once stabilised))
IV corticosteroids
Supportive tx: fluids, electrolytes, rewarming, oxygen
70
What are the 5 types of thyroid cancer?
```
Papillary (80%)
Follicular (10%)
Medullary (4%)
Lymphoma
Anaplastic
```
71
What are the characteristics of a papillary thyroid cancer?
Most common
Young females
Radiation exposure is a great risk factor
Psammoma bodies and Orphan Anne nuclei seen on microscopy
72
What are the characteristics of a follicular thyroid cancer?
Affcts middle aged women
| Hurthle cells seen on microscopy
73
What are the characteristics of a medullary thyroid cancer?
Association with MEN2 syndrome
| secrete calcitonin
74
What are the characteristics of a thyroid lymphoma?
Most common in females
| Usually occurs after pre-existing Hashimoto's thyroiditis
75
What are the characteristics of a anaplastic thyroid cancer?
Seen in elderly females
| Giant cells and pleomorphic hyerchromatic nuclei on microscopy
76
Define acromegaly
A disease caused by excess growth hormone production usually 2/2 pituitary adenoma
↑GH in children = Gigantism
↑GH in adults = Acromegaly
GH stimulates IGF-1 causing the growth of bone and soft tissue
77
What is gigantism?
Hypersecretion of growth hormone in children
78
What is the presentation of acromegaly in the arms/hands?
```
Ring and shoes become tight
Increased sweating
Spade-like hands
Clubbed nails
Carpel tunnel syndrome- excess soft tissue growth trapping the median nerve in the carpel tunnel
High BP
```
79
What are the investigations for acromegaly?
Serum IGF-1
OGTT -> failed GH supression
Pituitary MRI
80
What is the treatment for acromeglay?
Transphenoidal hypophysectomy
| Octreotide (somatostatin analogue)
81
What is multiple endocrine neoplasia?
AUTOSOMAL DOMINANT hereditary tumour syndromes characterised by development of numerous endocrine tumours in multiple organs
82
What is MEN1?
| PPP
MEN 1 mutation on Cr 11
Pituitary tumours: prolactinoma or GH
Pancreatic tumours: gastrinoma, insulinoma, zollinger-ellison syndrome
Parathyroid adenoma --> symptoms of hypercalcemia
83
What is MEN2A?
| PPM
2P’S + 1M associated with RET mutation
Parathyroid hyperplasia
Phaeochromocytoma (headache, palpitations, sweating)
Medullary Thyroid cancer: neoplasm of parafollicular cells calcitonin
84
What is MEN2B?
| PMMM
```
1P + 3Ms associated with RET mutation
Phaeochromocytoma
Medullary thyroid cancer
Marfanoid habitus
Mucosal neuroma (GI tract + mouth)
```
85
What is carcinoid syndrome?
Systemic symptoms caused by neuroendocrine tumours of the GIT which release serotonin (5-HT) and other vasoactive peptides.
86
What are the 2 common sites of carcinoid tumours?
1. GI tract- appendix + rectum
2. Lungs
GIT tumours do not normally produce symptoms as they undergo hepatic first pass metabolism.
Only symptomatic once the tumour has metabolised to the liver
87
What is the presentation for carcinoid syndrome? (CARCinoid)
- Cutaneous, paroxysmal flushing, sweating
- Asthmatic wheeze
- Right sided murmur, palpitations (cardiac fibroblast activation)
- Crampy abdo pain, diarrhoea
most common = DIARRHOEA + SOB + FLUSHING
88
What are the investigations for carcinoid syndrome?
24h urine collection- raised 5-HIAA levels (serotonin metabolite)
CT/MRI/endoscopy- localise tumour
89
A 49 year-old man presents with a history of difficulty sleeping. He reports feeling increasingly tired and general weakness which he attributes to his poor sleep pattern. Additionally, the patient has noticed he has gained weight and sweats more easily. On examination, the patient has coarse facial features. What is the most likely diagnosis?
```
A. Hyperthyroidism
B. Cushing’s disease
C. Acromegaly
D. Hypothyroidism
E. Diabetes
```
C. Acromegaly
90
A 50 year old Asian man is referred to diabetes clinic after presenting with polyuria and polydipsia. He has a BMI of 30, a blood pressure measurement of 137/88 and a fasting plasma glucose of 7.7mmol/L. The most appropriate first-line treatment is:
```
A. Dietary advice and exercise
B. Sulphonylurea
C. Exenatide
D. Thiazolidinediones
E. Metformin
```
A. Dietary advice and exercise
91
A 15 year old girl complains of headaches which started 6 weeks ago. The headaches initially occurred 1-2 times a week but now occur up to five times a week, they are not associated with any neurological problems, visual disturbances, nausea or vomiting. The girls also reports a white discharge from both of her nipples. She has not started menstruating. The most appropriate investigation is:
```
A. Lateral skull X ray
B. CT scan
C. MRI scan
D. Thyroid function tests
E. Serum prolactin measurement
```
E. Serum prolactin measurement
92
A 6 year old girl presents to A&E with severe abdominal pain, nausea and vomiting. On examination, the patient is tachypnoeic, capillary refill is 3 seconds and she has a dry tongue. While listening to the patient’s lungs you detect a sweet odour from her breath. The most likely diagnosis is:
```
A. Diabetic ketoacidosis
B. Non-ketotic hyperosmolar state
C. Gastroenteritis
D. Pancreatitis
E. Adrenal crisis
```
A. Diabetic ketoacidosis
93
A 58 year old woman presents with an acutely painful neck, the patient has a fever, blood pressure is 135/85, and heart rate is 102 bpm. The patient explains the pain started 2 weeks ago and has gradually become worse. She also experiences palpitations and believes she has lost weight. She presents one week later complaining of intolerance to cold temperatures. What would you see if you performed a radioisotope scan on her?
```
A. Single area of increased uptake
B. Multiple areas of increased uptake
C. Diffuse increased uptake
D. No uptake
E. She does not need a radioisotope scan
```
D. No uptake
94
A 72 year old man is brought to A&E because his carer noticed that recently he has become increasingly lethargic, irritable and confused. On examination he has a raised JVP and bibasal crackles. He suffered from a myocardial infarction 3 years ago.
Blood results are as follows:
Na 125 mmol/L
Urea 3
K 4 mmol/L
Glucose (fasting) 6 mmol/L
What is the most likely cause of his hyponatraemia:
```
A. SIADH
B. Hypothyroidism
C. Nephrotic syndrome
D. Heart failure
E. Diabetes
```
D. Heart failure
95
Most common cause of hyperthyroidism?
Grave's disease
| autoimmune - TSH Receptor Antibodies (TRAb)
96
Compare the goitres for the 4 causes of hyperthyroidism
- Grave's disease- diffuse, smoothly enlarged
- Toxic multinodular goitre- irregular/bumpy
- Toxic adenoma- single nodule (only one part of thyroid is enlarged)
- Thyroiditis- tender
97
Give an example of a disease causing increased thyroid hormone release. When is this seen?
De Quervain’s Thyroiditis
| Post-viral infection
98
What investigations would you do for hyperthyroidism?
Bedside: Thyroid exam, ECG (check for arrhythmias/ AF as a result of hyperthyroidism)
Bloods: ↓(supressed)TSH, ↑T3/T4
Imaging: Radioisotope scan- uptake of radioiodine by thyroid
99
management of thyroiditis
- Usually self-limiting
- NSAIDs for thyroid pain (corticosteroids if severe)
- Beta-blockers (symptom management)- CCB if contraindicated eg asthma
- May require additional therapy if pt severely hyper/hypothyroid (levothyroxine/potassium iodide)
100
management of Grave's
- Beta-blockers (symptom management)- CCB if contraindicated eg asthma
- Anti-thyroid drugs (carbimazole or propylthiouracil)- long-term use OR normalise thyroid function prior to radiotherapy/surgery
- Radioiodine therapy- if hyperthyroidism not controlled by ATDs
- Thyroidectomy
101
Name 2 anti-thyroid drugs
carbimazole
| propylthiouracil
102
What is a complication of anti-thyroid drugs?
agranulocytosis (type of neutropaenia)
103
2 methods of administering anti-thyroid drugs
1. Titre dose to achieve euthyroidism (normal TSH levels)
2. Follow a ‘block and replace regimen’ - completely block thyroid hormone production and replace hormones with levothyroxine.
104
2 key complications of hyperthyroidism
1. Thyroid storm
| 2. Atrial fibrillation- may develop into high-output cardiac failure
105
define thyroid storm
An acute and life-threatening presentation of thyrotoxicosis often caused by a precipitating event (infection, trauma, surgery etc.).
106
How does thyroid storm present?
```
fever
tachycardia
confusion/agitation
nausea
HTN
```
107
Management of thyroid storm (4Ps)
```
Propylthiouracil
Potassium Iodide (Lugol’s solution)
Propanolol
Prednisolone/hydrocortisone (steroids)
+ supportive tx and treatment of precipitating event
```
108
Which blood marker is elevated in medullary thyroid cancers? What symptoms may this marker cause?
calcitonin
opposes the action of PTH, causes:
- diarrhoea (increased GI motility)
- facial flushing
109
A 32-year-old woman presents to her GP with ongoing diarrhea and flushing. The GP carries out a full examination and finds a solitary thyroid nodule. The patient also has a strong family history of cancers and thyroid cancers.
```
Which of these markers might be elevated in the bloods of this patient? Go through the other options.
CEA
CA15-3
Calcitonin
Metenephrines
5-HIAA
```
Calcitonin is elevated in medullary thyroid cancers
Going through the other options:
- CEA is elevated in numerous cancer including colon cancer
- CA15-3 may be elevated in breast cancer
- Metenephrines may be elevated in phaeochromocytoma
- 5-HIAA is seen in carcinoid tumours
110
A patient is diagnosed with medullary thyroid cancer. Given she has a strong family history of thyroid and other cancers, it is thought she has a specific familial cancer syndrome.
What two other conditions are associated with this cancer syndrome?
Parathyroid hyperplasia and phaeochromocytoma
111
Medullary thyroid cancer is associated with which 2 syndromes?
What are the other conditions in these syndromes?
Multiple Endocrine Neoplasia syndrome:
MEN2A: 2Ps and 1M
Phaeochromocytoma
Medullary Thyroid cancer
Parathyroid hyperplasia
```
MEN2B: 1P and 3Ms
Phaeochromocytoma
Medullary Thyroid cancer
Marfanoid habitus
Mucosal neuromas
```
112
Causes of hypothyroidism
Autoimmune Hashimoto’s Thyroiditis (commonest cause in developed countries)
Iodine Deficiency (commonest cause worldwide)
De Quervain’s Thyroiditis: Transient hypothyroidism --> hypothyroidism
Iatrogenic: post-thyroidectomy, amiodarone, lithium
Congenital thyroid syndromes
113
drugs causing hypothyroidism
amiodarone (antiarrhythmic), lithium
114
Investigations for hypothyroidism
free T3/4 = low
TSH = high
sodium may be low, glucose may be high (T1DM)
115
```
A 68-year-old woman is admitted to A/E with acute confusion. On examination, she is overweight, there is non-pitting oedema affecting the eyes and legs, and she has dry skin and coarse hair. She has a heart rate of 50 beats/min, blood pressure of 90/60mmHg, respiratory rate of 10 breaths/min, temperature of 30°C, and oxygen saturation of 90% on air.Which of these medications should she be started on?
Propylthiouracil
IV Propanalol
Enalapril
IV Liothyronine sodium
Octreotide
```
IV infusion with liothyroxine sodium and supportive treatment e.g. rewarming, fluids etc.
Going through the other options:
- Proylthiouracil and Propanalol can be used for hyperthyroidism and thyroid storm.
- Enalapril may be used for heart failure
- Octreotide is a somatostatin analogue which inhibits TSH and GH release from the pituitary
116
Medullary thyroid cancer is a carcinoma of which cells? What do these cells secrete?
parafollicular (C) cells
| These secrete calcitonin
117
Presentation of thyroid cancer
- Palpable thyroid nodule
- compression symptoms- hoarseness, dyspnoea, dysphagia
- cervical lymphadenopathy
- most nodules are cold (hypofunctioning) but can be hot
118
What is an important aspect of a thyroid cancer history?
FHx- strong genetic component, especially medullary cancer
119
Investigations for thyroid cancer
- TSH
- USS neck to characterise nodules + check number
- Fine needle biopsy for histology
120
How do carcinoid tumours cause flushing + hypotension?
Serotonin and vasoactive peptide released from tumours cause vasodilation
121
How do carcinoid tumours cause wheeze?
serotonin causes bronchoconstriction
122
How do carcinoid tumours cause R sided murmur (and not left?)
From the GI tract/liver mets, serotonin travels to RHS of heart
causes fibrosis of the valves (fibroblast activation)
--> pulmonary stenosis or mitral regurgitation
serotonin is broken down into inactive metabolites by MAO in the lungs before it reaches the LHS heart.
123
How do carcinoid tumours cause diarrhoea/cramps?
Serotonin regulates peristalsis and digestive secretions
124
which enzyme breaks seratonin down into what inactive metabolites?
Broken down by MAO enzymes
5-Hydroxyindoleacetic acid (5-HIAA) is the main metabolite of 5-HT
125
What is the presentation of acromegaly in the face/head?
Course facial features: frontal bossing, broad nose, thick lips, prognathism (protruding jaw),
Mouth: Macroglossia (enlarged tongue), increased interdental spaces
Diaphoresis (increased sweating)
Signs of pituitary enlargement: homonymous hemianopia (compression on optic chiasm), headache, signs of hypopituitarism
126
What is the presentation of acromegaly in the neck?
Deep voice
| Sleep apnoea > snoring
127
What is the presentation of acromegaly in the chest/abdo?
Galactorrhoea
Reduced libido, infertility, ED (co-existent prolactinoma in 1/3 cases)
Increased risk of colorectal polyps and cancer
Impaired glucose tolerance (insulin resistance + diabetes)
128
List common complications of acromegaly
Diabetes
Hypertension
Cardiomyopathy
Colorectal cancer
129
Investigations for acromegaly
Bedside: examination, BP, BMs
Bloods:
- Increased serum IGF-1
- Failure to suppress GH following OGTT (first-line)
- Don’t tend to measure GH as it varies throughout the day while IGF-1 is more stable and has a long half-life.
- May also measure other pituitary hormones to check for hypopituitarism or co-secreting tumours.
Imaging: MRI- pituitary mass
130
First line management of acromegaly
Trans-sphenoidal hypophysectomy
131
medical management of acromegaly
If the tumour is inoperable or surgery is unsuccessful:
- Somatostatin analogues (octreotide)- directly inhibits the release release of GH.
- Growth hormone-receptor antagonist (pegvisomant)- , prevents dimerisation of the GH receptor
- Dopamine agonists (bromocriptine/cabergoline)- effective in a minority of patients (eg with prolactinomas)
132
A 49-year-old gentleman presents to his GP with a one-month history of headache, sweating and visual problems. He mentions that he has noticed a change in his appearance compared with old photos and that his wedding ring no longer fits.Given the likely diagnosis, which of the following would be the most appropriate first-line investigation?
```
Pituitary MRI
Serum IGF-1
Serum Growth Hormone
Serum prolactin
Short synACTHen test
```
Acromegaly
First-line investigation is IGF-1
Pituitary MRI would then confirm the diagnosis
The other options:
Serum prolactin used for prolactinoma.
Often check serum prolactin too, as this often co-exists with acromegaly
Short synACTHen test used to diagnose adrenal insufficiency
133
A 19-year-old boy presents to the clinic concerned he hasn’t gone through puberty. He has a normal stature, has not developed facial hair and complains of an inability to smell. On examination his testes are undescended.
```
Based on this information what is the likely diagnosis?
Klinefelter’s syndrome
Kallman’s syndrome
Prader-Willi syndrome
Turner’s Syndrome
Precocious puberty
```
Kallman’s syndrome (hypogonadism)
134
Define hypogonadism
A clinical syndrome that presents with infertility and sex hormone deficiency
135
Clinical symptoms of hypogonadism in females
```
Delayed puberty
Amenorrhoea
Infertility
↓ Libido
Night sweats, hot flushes, dyspareunia
Symptoms of cause
```
136
Summarise the pituitary gonadal axis
hypothalamus > GnRH
Ant pituitary > LH + FSH
Gonads > oestrogen + progesterone (negative feedback)
137
Primary causes of hypogonadism
- Gonadal dysgenesis- Turner’s Syndrome (XO)
- Gonadal damage- radio/chemotherapy, surgery, autoimmune damage
- Primary ovarian failure (premature ovarian insufficiency)- ovaries stop working before age 40 (early menopause)
- PCOS
138
Secondary causes of hypogonadism
Problem with hypothalamus/pituitary
Kallman’s syndrome- failure of GnRH neurone migration > decreased GnRH secretion
Pituitary/hypothalamic problems e.g. pituitary adenoma or haemochromatosis (infiltration)
Hyperprolactinaemia: suppresses GnRH release
Functional: stress, weight loss, eating disorders.
Post OCP
139
Pre-pubertal characteristics of hypogonadism
primary amenorrhoea, no secondary sexual characteristics
140
Post-pubertal characteristics of hypogonadism
regression of secondary sexual characteristics
141
What is the hallmark feature of Kallman's syndrome?
Ansomia
142
What are the hallmark features of Turner's syndrome?
webbed neck
| short stature
143
What are the hallmark features of hyperprolactinaemia?
galactorrhoea
| visual field defects
144
What investigations would you do for hypogonadism in FEMALES?
Pregnancy test
Bloods:
- ↓Oestrdiol
- 1o hypogonadism: ↑LH/FSH
- 2o hypogonadism: ↓LH/FSH
- Prolactin
- TFTs
PRIMARY: Genetic testing, pelvic MRI/USS
SECONDARY: Pituitary function tests, MRI
145
Presentation of hypogonadism in males
```
Delayed puberty
Erectile dysfunction
Infertility
↓ Libido
Symptoms of cause
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146
Primary causes of primary hypogonadism in males
- Gonadal dysgenesis e.g
- Klinefelter’s, cryptorchidism (undescended testes)
- Gonadal damage (torsion, irradiation, trauma)
- Post orchitis (mumps, auto-immune)
147
Secondary causes hypogonadism in males
Kallman’s syndrome
Pituitary/ Hypothalamic lesions
Hyperprolactinaemia
Prader-Willi syndrome
148
Signs of male hypogonadism
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PRE-PUBERTAL:
no secondary sexual characteristics
High-pitched voice
Small/ undescended testes
Small penis
Eunuchoid proportions
Decreased pubic/ facial hair
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POST-PUBERTAL:
loss of hair
gynaecomastia
headaches
visual field defects
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149
Investigations for hypogonadism in males
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Bloods:
Serum testosterone
Sex hormone binding globulin
LH/ FSH
Prolactin
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Genetic Testing
MRI pituitary
