Endocrine

Question 1

Causes of a goitre

Answer 1

1. Idiopathic (majority)
2. Puberty, pregnancy, post-partum
3. Grave’s disease
4. Thyroiditis: Hashimoto’s thyroiditis, subacute thyroiditis (tender), chronic fibrosing (Riedel’s) thyroiditis
5. Simple goitre (iodine deficiency)
6. Goitrogens: iodine excess, drugs (lithium)

Question 2

Diagnosis of acromegaly

Answer 2

BIOCHEMICAL
1. Insulin-like growth factor level in plasma
2. Glucose tolerance test (no suppression)
ANATOMICAL
3. MRI BRAIN (Pituitary tumour)

Question 3

Acromegaly evidence of activity/severity.

Answer 3

1. Skin tag number
2. Excessive sweating
3. Presence of glycosuria
4. Increasing visual field loss or development of cranial nerve palsies
5. Enlarging goitre
6. Hypertension
7. Symptoms of headache, or increasing ring size, shoe size or dentures

Question 4

Clinical features of autonomic neuropathy

Answer 4

● Postural hypotension (a BP fall of >30/20mmHg on standing upright from a supine position)
● Loss of sinus arrhythmia
● Valsalva manoeuvre causes no slowing of the pulse
● Loss of sweating
● Erectile dysfunction
● Nocturnal diarrhoea
● Urine retention, incontinence

Question 5

Features of proliferative and non-proliferative diabetic retinopathy

Answer 5

NON-PROLIFERATIVE
● Haemorrhages:
o Dot haemorrhage into the inner retinal areas
o Blot-haemorrhage into more superficial nerve fibre areas
o Hard exudates have straight edges – leakage of protein and lipids from damaged capillaries
o Soft exudates (cotton wool spots) have a fluffy appearance owing to microinfarcts
o Microaneurysms
o Dilated veins
PROLIFERATIVE
● New vessels
● Vitreous haemorrhage
● Scar formation
● Retinal detachment
● Laser scars (small brown or yellow spots)

Question 6

Causes of Hyperthyroidism

Answer 6

Primary: 
Graves' Disease 
Toxic adenoma
Multinodular goitre
Thyroiditis: Hashimotos, subacute
Iodine induced (after previous iodine deficiency) 
Excess thyroid hormone replacement
 Postpartum thyroiditis (non tender) 
Drugs: amiodarone, lithium

Secondary:

1. Pituitary or ectopic TSH hypersecrection
2. Hydatidiform mole or choriocarcinoma (HCG secretion - rare)
3. Struma ovarii
4. Factitious

Question 7

Causes of hypothyroidism

Answer 7

PRIMARY
Without a goitre (decreased or absent thyroid tissue)
Idiopathic atrophy
Treatment (e.g. iodine-131, surgery)
Agenesis, lingual thyroid 
Unresponsiveness to TSH
With a goitre (decreased synthesis)
Chronic thyroiditis: late Hashimoto's, Riedel's thyroiditis
Drugs: lithium, amiodarone
Endemic iodine deficiency
Iodine-induced hypothyroidism
Inborn errors (enzyme deficiency)

SECONDARY- Pituitary lesions
TERTIARY- Hypothalamic lesions
TRANSIENT- Thyroid hormone treatment withdrawl- Subacute thyroiditis- Postpartum thyroiditis

Question 8

Neurological side effects of hypothyroidism

Answer 8

Common
Entrapment - carpal tunnel, tarsal tunnel
Delayed relaxation phase of ankle jerks
Nerve deafness

Uncommon
Peripheral neuropathy
Proximal myopathy 
Hypokalemic periodic paralysis
Eaton-lambert syndrome 
Unmasking of myasthenia gravis
Cerebellar syndrome
Psychosis
Coma
Cerebrovascular disease
High CSF
Muscle cramps

Question 9

Signs of panhypopituitarism

Answer 9

Short stature, reduced body hair, increased abdominal fat
short if failed GH secretion before growth complete
Partial breast development
may have no secondary sexual characteristics if gonadotrophin failure before puberty
Absence of axillary/pubic hair
look for testicular atrophy in men
Face - multiple, fine skin wrinkles around the eyes and mouth are characteristic of GH deficiency hypophysectomy scar on forehead near the inner canthus
Eyes - pituitary tumour: bitemporal hemianopia, optic atrophy; 3/4/V1/6 (tumour extension into cavernous sinus)
ankle jerks for slow relaxation of hypothyroidism
BP with postural for ACTH deficiency

Question 10

Causes of Addisons disease

Answer 10

Iatrogenic
Primary
Autoimmune in >80%
polyglandular syndrome I: APECED (addison’s, hypoparathyroid, mucocutaneous candidiasis, primary hypogonadism)
polyglandular syndrome II: addison’s, T1DM, hashimoto’s or graves’, primary hypogonadism
infection: waterhouse-friderichsen syndrome (neisseria, TB), histoplasmosis
infiltration: amyloid, sarcoid, malignant disease
demyelination: adrenoleukodystrophy (addison’s + asymmetrical cortical signs), adrenomyeloneuropathy (addison’s + spastic paraparesis)
drugs: heparin, ketoconazole
Secondary (usually no mineralocorticoid deficiency)
pituitary
hypothalamic

Question 11

Causes of hirsutism

Answer 11

Constitutional (normal endocrinology)
PCOS
Adrenal - cushing’s - CAH (21 or 11 hydroxylase deficiency) - virilising adrenal tumour
Ovarian - stromal ovarian cancer
Drugs - phenytoin, diazoxide, streptomycin, minoxidil, androgen, glucocorticoids
Other - acromegaly, PCT