Endocrine

Question 1

Diabetes Inspidius

Answer 1

Central DI results from impaired production, transport or release of ADH.
Nephrogenic DI results from inability of the renal collecting ducts to respond to ADH.
Both cause defective water reabsorption in kidneys = excessive production of dilute, hypotonic urine.
S: Polydypsia, Polyuria, Dehydration, Hyponatraemia
D: Water deprivation test, Desmopressin stimulation test
T: CDI requires desmopressin and oral/IV fluids, NDI requires low Na diet, thiazide and NSAIDs

Question 2

Hyperthyroidism

Answer 2

Overproduction of T3 and T4
Caused by Graves’ disease or Toxic multinodular Goitre.
S: Sweating, weight loss, increased bowel movements, anxiety, irritability, palpitations, oligomenorrhea, lid lag.
D: TFTs (low TSH, high T3)
T: Carbimazole (decreases T hormone synthesis), Radioiodine (kills thyroid cells), Thyroidectomy

Question 3

Hypothyroidism

Answer 3

Underactivity of the thyroid gland
Caused by Hashimoto’s thyroiditis, thyroid atrophy, Post-partum thyroiditis, Iatrogenic, Drug-induced, Congenital hypothyroidism.
S: lethagry, low mood, cold-disliking, weight gain, constipation, menorrhagia, decreased memory/cognition, weakness, bradycardia, dry skin, cold peripheries, puffy face, ascites.
D: TFTs (high TSH, low free T4), anaemia, hyperlipidaemia, hyponatraemia
T: Levothyroxine at a daily dose of 1.6 μg/kg body weight

Question 4

Growth hormone deficiency

Answer 4

Pituitary gland fails to release enough growth hormone (somatotropin).
Can be idiopathic, or caused by Prader-Willi syndrome, Turner’s syndrome, trauma, infection, radiation therapy damaging the hypothalamus or pituitary gland, pituitary tumour.
S in children: hypoglycaemia, short stature, delayed bone age, decreased muscle development.
S in adults: weakened muscles, low bone density, depression, poor memory, social withdrawal.
D: Measure GH, IGF, X-ray
T: Growth hormone therapy

Question 5

Hyperparathyroidism

Answer 5

Overproduction of the parathyroid hormone
Primary - parathyroid adenoma due to genetic mutation, hyperplasia, carcinoma
S: kidney stones or gallstones, polyuria, chronic bone pain, constipation, depression
Secondary: excess parathyroid hormone in response to chronic hypocalcaemia
S: CKD (usually the cause), renal osteodystrophy, calcification in blood vessels
Tertiary: Develop primary from secondary
S: Same as primary, elevated phosphate
D: Measure parathyroid hormone, phosphate, calcium, vit D.
T: Remove the parathyroid glands or calcimimetics if primary or tertiary, phosphate binders, supplements and calcitriol analogues if secondary.

Question 6

Hypoparathyroidism

Answer 6

Underproduction of parathyroid hormone.
C: thyroid/parathyroid surgery, Autoimmune polyendocrine syndrome type 1, DiGeorge syndrome, genetics (auto dom), Pseudohypoparathyroidism type 1a.
S: hypocalcaemia and hyperphosphatemia, tetany, paraesthesia, changes in cardiac output, calcification in the basal ganglia and the lens of the eye, Chvotek’s sign, Trousseau’s sign.
D: parathyroid hormone, calcium, vitamin D, albumin, phosphorus, magnesium, Prolonged QT, prolonged ST segment or arrhythmias on ECG.
T: Calcium and Vitamin D supplements
Recombinant human parathyroid hormone

Question 7

Hyperaldosteronism

Answer 7

Adrenal gland produces too much aldosterone.
1 causes: Idiopathic, Conn syndrome, Familial
2 causes: High levels of renin, chronic low blood pressure e.g. congestive heart failure or cirrhosis
Hyperaldosteronism leads to hypokalaemia and hypernatremia and high blood vol and high blood pressure.
S: hypertension-related symptoms like headaches and flushing and hypokalaemia-related symptoms like constipation, weakness and heart changes in rhythm.
D: Measuring levels of renin and aldosterone
T: Potassium-sparing diuretics, Treating underlying cause e.g. removing tumour in Conn syndrome, managing heart failure and cirrhosis

Question 8

Addison’s disease

Answer 8

Adrenal gland is unable to produce enough aldosterone or cortisol due to the adrenal gland itself.
Causes: damage to adrenal cortex due to autoimmune destruction, TB, metastatic carcinoma.
S: Depends on the area damaged
ZG: aldosterone falls, hyperkalaemia and hyponatremia, hypovolaemia, metabolic acidosis, cravings for salty foods, nausea and vomiting, fatigue, dizziness.
ZF: weak, tired, disorientated, overactive pituitary gland leading to hyperpigmentation
ZR: women can experience a loss of pubic and armpit hair and a decreased sex drive
Addisonian crisis: sudden pain in the lower back, abdomen or legs with severe vomiting and diarrhoea, followed by hypotension, dehydration and loss of consciousness.
D: ACTH stimulation test
T: Hormones - aldosterone, cortisol, androgens taken for life

Question 9

Cushing’s syndrome

Answer 9

Elevated cortisol levels in the blood.
Causes: Steroid medications that mimic the action of cortisol (endogenous), excess ACTH caused by a pituitary adenoma (Cushing disease), small cell lung cancer, adrenal adenomas and carcinomas.
S: Muscle wasting, thin extremities, skin thinning and easy bruising, abdominal striae, fractures due to osteoporosis, ‘full moon’ face, ‘buffalo hump’ back, truncal obesity, hyperglycaemia.
D: Measuring free unbound cortisol in the urine over 24 hours, Dexamethasone suppression test, ACTH plasma levels, MRI of the pituitary gland, CT of the adrenals, CT of the chest, abdomen or pelvis.
T: Exogenous medications, surgical excision of the adrenals, adrenal steroid inhibitors

Question 10

Pituitary adenoma

Answer 10

A tumour that develops in the hormone-producing cells of the pituitary gland. Sits just behind the eyes.
Can be a Microadenoma (<1cm) or a Macroadenoma (>1cm).
Most common is a prolactinoma - causes amenorrhoea and galactorrhoea in women and low libido and gynecomastia in men.
Pituitary adenoma in the somatotrophs causes gigantism in children and acromegaly in adults.
A ACTH-secreting tumour leads to Cushing’s disease.
D: Measuring pituitary hormone levels, MRI
T: Prolactinomas are usually treated with medication, Somatotropic and corticotropic - usually require transsphenoidal surgical resection, non-functional tumours compressing other structures may require surgery.

Question 11

Acromegaly

Answer 11

Hormonal disorder in adults where there is excess growth hormone (somatotropin) which causes the continued growth of the extremities (large face, hands and feet).
C: Pituitary adenoma, Hypothalamic tumours, multiple endocrine neoplasia type 1.
S: Growth of the bones of the hands, feet and lower jaw, Protrusion of the forehead, Soft tissue swelling in the hands, feet, face and tongue, Increased size of the organs, Excess sweating
D: Increased levels of insulin-like growth factor 1 and GH in spite of receiving a large dose of glucose, MRI
T: Pituitary adenoma - surgery/radiation therapy
Somatostatin analogues or GH receptor antagonists

Question 12

Prolactinoma

Answer 12

Benign tumour of the pituitary gland that secretes excess prolactin.
<10mm = Microprolactinomas - asymptomatic
>10mm = Macroprolactinomas - headaches, bitemporal hemiopia
In women, galactorrhoea, amenorrhea, vaginal dryness, brittle bones
In men, gynecomastia, erectile dysfunction
Both sexes can experience decreased libido and infertility
D: elevated levels of prolactin in the blood, MRI
T: Dopamine agonists - Bromocriptine and Cabergoline, Surgery, Radiation therapy

Question 13

Diabetes mellitus

Answer 13

A metabolic disorder characterised by chronic hyperglycaemia due to the lack of insulin.
C: T1 due to autoimmune destruction of insulin producing beta cells, T2 due to ‘secretory exhaustion’ of beta cells caused by obesity.
S: Polyuria, polydypsia, recurrent UTIs and skin infections, T1 can present as diabetic ketoacidosis, nephropathy, neuropathy, retinopathy, vascular disease, foot ulcers.
D: Fasting plasma glucose of more than 7 mmol/L or a random plasma glucose more than 11.1 mmol/L. In borderline patients, do a oral glucose tolerance test.
T: T1 (daily injection basal bolus insulin regime, dietary control), T2 (lifestyle changes, metformin, can add sulfonylureas, meglitinide, thiazolidinedione, gliptin, SGLT-2 inhibitor, or GLP-1 receptor agonist)

Question 14

Hypocalcaemia

Answer 14

Normal blood calcium levels: 8.6-10.3mg/dL (2-2.5mmol/L) in Hypocalcaemia: <8.5mg/dL, (<2mmol/L)
C: Hypoparathyroidism (post-surgery, idiopathic, congenital, HIV), Pseudohypoparathyroidism (PTH resistance), decreased vit D or Mg, CKD, acute pancreatitis, acute rhabdomyolysis, bisphosphonates, chemo.
S: Spasms, Perioral paraesthesiae, Anxiety, Seizures, Muscle tone increased, Orientation impaired, Dermatitis, Impetigo herpetiformis, Chvostek’s sign and cardiomyopathy
D: serum phosphate, magnesium, calcium, PTH, vitamin D levels, corrected calcium, ECG (prolonged QT interva, arrhythmias)
T: give calcium 5mmol/6hr PO, with daily plasma Ca2+ levels, alfacalcidol in CKD, if severe 10mL 10% calcium gluconate IV over 30mins.

Question 15

Hypercalcaemia

Answer 15

Serum calcium concentration of 2.6mmol/L or higher on 2 occasions (following correction for serum albumi).
C: Hyperparathyroidism (osteoclast breakdown), malignant tumours release PTHrP (mimics PTH), excess vitamin D, thiazides
S: Stones (renal), Bones (pain, fractures, osteoporosis), Moans (confusion, fatigue, depression), Groans (abdo pain, pancreatitis, peptic ulcer disease)
D: serum phosphate, magnesium, calcium, PTH, vitamin D levels, corrected calcium, ECG (short QT interval, bradycardia, AV block), bone scan, 24hr urinary Ca2+ excretion
T: Required if >15mg/dL. Treat underlying cause. Rehydrate to encourage Ca excretion, loop diuretics e.g. furosemide and bisphosphonates to prevent bone resorption.

Question 16

Hypoglycaemia

Answer 16

Defined by Whipple’s triad plasma hypoglacaemia (<3.0 mmol/L), symptoms of low glucose, resolution of symptoms with correction.
C: Alcohol, poor glycaemic control, drugs and toxins, pancreatic insulin tumours, extra pancreatic IGF-II-secreting neoplasms, autoimmune, reactive, starvation, hormone-deficiencies, self-induced.
S: Shaking, sweating, pins and needles in mouth, palpitations, headache, double vision, slurring of speech, confusion, change of behaviour, coma.
D: HbA1c, LFTs and TFTs, 72-hour fast and prolactin levels if insulioma is suspected, CT scan, endocrine investigations.
T: Glucose 10-20g (liquid, sugar, glucogel) or IV glucose, or SC/IM 1mg glucagon. Once more alert, give a meal or infusion of 10% glucose with regular insulin dose. In coma, IV mannitol and dexamethasone with constant glucose monitoring and IV glucose. Treatment of underlying cause - alcohol abuse, medication review, diet review, removal of insulin-secreting tumour.

Question 17

Hypercholesterolaemia

Answer 17

Elevated levels of low-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol.
C: Diet, stress, T2 diabetes, obesity, alcohol use, dialysis therapy, nephrotic syndrome, hypothyroidism, cushing’s syndrome, anorexia, medications, genetics (familial)
S: Asymptomatic, ischaemia causing loss of vision, dizziness and impairment of balance, difficulty speaking, weakness or numbness or tingling, calf pain, chest pain, abdominal pain after a meal, xanthelasma, xanthomata
D: Cholesterol levels, routine screening
T: Lifestyle changes, for familial restrict intakes of total fat to 25–35% of energy intake, saturated fat to less than 7% of energy intake, and cholesterol to less than 200 mg per day, statins.

Question 18

Hypernatraemia

Answer 18

Serum sodium concentration exceeding 145 mmol/L.
C: dehydration (DI, lack of water, dementia, hypothalamic lesions), hypovolaemia (burns, excessive sweating, GI loss, urinary loss), hypertonic sodium gain (IV antibiotics, excessive Na intake, hyperaldosteronism)
S: DI (polydipsia, polyuria) CNS (lethargy, weakness, confusion, irritability, myoclonic jerks and seizures), hypovolaemia (dry mouth, abnormal skin turgor, oliguria, tachycardia, orthostatic hypotension).
D: serum sodium, potassium, urea, creatinine, calcium and plasma glucose, lithium levels, urine and serum osmolality, neuroimaging.
T: Address the underlying cause - stop gastrointestinal fluid losses, control pyrexia, correct hyperglycaemia, withhold lactulose and diuretics.
Active correction - fluids should be administered orally or enterally and intravenous therapy used only as a last resort.

Question 19

Hyponatraemia

Answer 19

A relative excess of water in relation to sodium and is defined as a serum sodium <136 mmol/L. <120 is severe.
C: Isotonic (hyperproteinemia, hyperlipidaemia), hypotonic hypovolamic (extrarenal and renal salt loss), hypotonic euvolaemic (SIADH, hypothyroidism, post-op, endurance exercise, drug reaction), hypotonic hypervolaemic (HF, liver or kidney diseasse) hypertonic (hyperglycaemia, mannitol, sorbitol, glycerol, maltose, radiocontrast agents).
S: Asymptomatic, anorexia, headache, nausea, vomiting, lethargy, personality change, cramps, weakness, confusion, drowsiness, seizures.
D: Fluids status, BP, HR, cardio exam, serum Na and K, TFTs, urine Na level, random serum cortisol levels or ACTH stimulation test.
T: Hypovolaemic - IV saline replacement. Normovolaemic - fluid restrict, use of vaptans
Hypervolaemic - treat the underlying cause (usually heart failure, AKI, liver cirrhosis), loop diuretics.

Question 20

Hypokalaemia

Answer 20

Serum potassium concentration of <3.5 mmol/L.
C: Increased renal excretion (diuretics, hypomagnesaemia, renal disease), GI losses, alkalosis, B-agonists, insulin (redistribution to the cells), reduced intake.
S: Asymptomatic, muscle weakness, heart arrythmias.
D: U&Es, serum Mg, Cl, bicarb, glucose, ECG (flat T waves, ST depression, prominent U waves), urinary K, Na, osmolarity
T: Treat underlying cause, review diuretics, replacement with oral potassium chloride supplements, Mg should be normalised. IV potassium chloride (in NaCl) for patients with hypokalaemia and DKA or severe hypokalaemia with cardiac arrythmias or muscle weakness.

Question 21

Hyperkalaemia

Answer 21

Serum potassium of concentration >5.5 mmol/L.
C: Decreased excretion (AKI, drugs, Addison’s disease), redistribution (DKA, metabolic acidosis, tissue necrosis or lysis), extraneous blood load (potassium chloride, salt substitutes, transfusion of stored blood)
S: Very few until cardiac arrest, muscle weakness and paralysis, metabolic acidosis.
D: Serum potassium, 24-hour urine volume and electrolytes, FBC, plasma glucose, Digoxin level, ABG, ECG (peaked T waves, prolongation of PR interval, widening of QRS).
T: Mild (dietary potassium restriction, restriction of drugs causing hyperkalaemia and a loop diuretic to increase urinary potassium excretion).
Emergency - IV calcium gluconate bolus (to protect heart), soluble insulin 10 units+50 mL 50% dextrose intravenously, sodium bicarbonate.
LT - Polystyrene sulphonate resin orally or rectally. Treat underlying cause. Review medication. Haemodialysis or peritoneal dialysis if conservative measures fail.

Question 22

Volume depletion

Answer 22

Loss of total body sodium causes loss of water across plasma membranes. Serum sodium concentration can be high, low, or normal.
C: Extrarenal (bleeding, dialysis, D&V, burns, excessive sweating, intestinal lumen, intraperitoneal, retroperitoneal losses)
Renal, adrenal and pituitary (AKI, adrenal disorders, genetic disorders, diuretics, salt-wasting disease)
S: Diminished skin turgor, oliguria, thirstiness, dry mucus membranes, orthostatic tachycardia, hypotension, shock.
D: Clinical findings, serum electrolytes, BUN (blood urea nitrogen), and creatinine
T: Replacement of sodium and water - orally if possible, tube feeding, IV fluids.

Question 23

Hypertriglyceridaemia

Answer 23

High blood levels of triglycerides. Increased risk of cardiovascular disease.
C: Obesity, diabets mellitus, excessive alcohol, kidney failure, lipoprotein lipase deficiency, lysosomal acid lipase deficiency, hypothyroidism, SLE, medications.
S: Asymptomatic, eruptive xanthoma, eye abnormalities (lipemia retinalis), hepatosplenomegaly (enlargement of the liver and spleen), and neurological symptoms.
D: Triglyceride levels - normal level is less than 150 mg/dL (1.7 mmol/L), identify underlying cause.
T: Lifestyle changes, drugs: Niacin, omega-3 fatty acids (epanova), statins, fibrates.

Question 24

Thyroid cancer

Answer 24

Uncommon but most common endocrine cancer.
Types: Papillary, follicular, (more common and treatable) Hürthle cell carcinoma, medullary, anaplastic (less common, aggressive), thyroid lymphomas.
C: Ionising radiation, history of goitre, thyroid nodule or thyroiditis, fhx of thyroid disease, Cowden’s syndrome, obesity, Familial adenomatous polyposis.
S: Hard and fixed thyroid nodule, non-tender, firm cervical masses (lymph node metastasis), vocal cord paralysis.
D: TFTs, serum calcitonin, ultrasound, fine-needle aspiration cytology, CT/MRI
T: Total thyroidectomy for tumours greater than 4cm, DTC - near-total thyroidectomy, followed by administration of iodine-131, thyroid suppression therapy.
MTC - total thyroidectomy and prophylactic central lymph node dissection, radiotherapy and chemo-embolisation for metastasis.
No effective treatment for ATC.

Question 25

Thyroid storm

Answer 25

Extreme manifestation of thyrotoxicosis due to overproduction of thyroid hormones. Occur in patients with toxic adenoma, multinodular toxic goitre, Graves’ disease.
C: infection, withdrawal of antithyroid medication, recent trauma, MI, stroke, DKA, hypo, childbirth, PE, radio-iodine, amiodarone, radiographic contrast media, surgery, vigorous palpation.
S: Pyrexia, dehydration, tachycardia, hypotension, atrial arrhythmias, HF, nausea, jaundice, abdo pain, confusion, delirium, coma.
D: TFTs (T3, T4), look for underlying precipitant, FBC, calcium and glucose levels, ECG, CXR, ABG
T: Antithyroid treatment - Carbimazole or propylthiouracil. After 4 hours give Lugol’s solution. Beta-blockers. Hydrocortisone administration, symptomatic - oxygen, IV fluids, NG tube, chlorpromazine for agitation, paracetamol and tepid sponging.

Question 26

Hypomagnesaemia

Answer 26

Mg levels less than 0.7 mmol/L.
C: Malabsorption syndromes (coeliac, Crohn’s, UC, chronic diarrhoea, short bowel), malnutrition, parathyroid gland disorders, chronic alcoholism, long-term PPIs, medications, renal disorders, diabetes, acute pancreatitis, refeeding, burns.
S: Symptomatic below 0.5. Weakness and apathy, Tremor, Paraesthesia, Tetany, Muscle fasciculations, Seizures, drowsiness, confusion and coma, arrhythmias.
D: Serum Mg level, Ca, K, PO, glucose levels, ECG (wide QRS complexes, a prolonged QT interval, flattened T waves and the presence of U waves), 24 Mg excretion, Mg infusion test.
T: Identify and treat underlying cause. Review medications. Oral replacement therapy or IV replacement with magnesium sulphate.

Question 27

Metabolic acidosis

Answer 27

Arterial blood pH <7.35 with plasma bicarbonate <22 mmol/L. Respiratory compensation may be partial or full.
C: Increased acid load (lactic acidosis, ketoacidosis, poisoning), impaired excretion (renal failure, hypoaldosteronism), excessive loss of GI bicarb (diarrhoea, fistulae, surgery), excessive loss of renal bicarb (acetazolamide or other carbonic anhydrase inhibitors).
S: Dyspnoea in an attempt to blow off CO2, nausea, vomiting, anorexia, lethargy, Kussmaul’s respiration, hypotension.
D: U&Es, ABG, K levels (usually accompanied by hyperkalaemia), plasma and urinary glucose and ketones, FBC, LFTs, ECG, CXR
T: Rehydrate using IV fluids, treat poisoning if present, treat underlying cause.

Question 28

Metabolic alkalosis

Answer 28

A primary acid-base disorder that causes the plasma bicarbonate to rise to an abnormally high level.
Chloride-responsive alkalosis results from loss of hydrogen ions or Chloride-resistant alkalosis results when your body retains too many bicarbonate ions.
C: Loss of stomach acids due to vomiting, excessive antacids, diuretics, hypokalaemia, reduced volume of blood in the arteries, heart/kidney/liver failure, genetic causes.
S: Vomiting, diarrhoea, peripheral oedema, fatigue, agitation, seizures, coma.
D: ABG, urinalysis
T: Chloride-responsive: Increased oral or IV intake of salt.
Chloride-resistant: Increase potassium intake through potassium pills or IV potassium chloride

Question 29

Respiratory acidosis

Answer 29

Occurs when the lungs can’t remove enough CO2 produced by the body. Excess CO2 causes the pH of blood and other bodily fluids to decrease, making them too acidic.
C: Acute (lung disorders, muscle weakness, airway obstruction, sedative overdose, cardiac arrest), Chronic (asthma, COPD, severe obesity, neuromuscular disorders, sciolosis.
S: Headache, anxiety, blurred vision, restlessness, confusion, fatigue, SOB, coma, changes in behaviour, memory loss.
D: ABG, electrolyte levels, LFTs, CXR
T: Address underlying cause, may need artificial ventilation, for chronic may need antibiotics, diuretics, bronchodilators, corticosteroids, mechanical ventilation.

Question 30

Respiratory alkalosis

Answer 30

Occurs when you breathe too fast or too deep and carbon dioxide levels drop too low. This causes the pH of the blood to rise and become too alkaline.
C: Hyperventilation due to MI, pain, drug use, asthma, fever, COPD, infection, PE, pregnancy, anxiety and panic attacks.
S: Dizziness, bloating, numbness, muscle spasms, chest discomfort, confusion, dry mouth, dyspnoea, heart palpitations, tingling in the arms.
D: ABG
T: Treat the underlying cause, reduce hyperventilation by breathing into a paper bag, reassurance.

Question 31

Volume excess

Answer 31

The circulating volume is excessive (more than the heart can cope with). Results in heart failure, which usually manifests as pulmonary and peripheral oedema.
C: Iatrogenic (IV fluids, blood transfusions), heart failure, AKI, increased ADH secretion, responses to physiological stress (injury/surgery).
S: Pulmonary oedema, acute dyspnoea, fatigue, dyspnoea and pitting oedema in a HF picture.
D: ECG (arrhythmias, infarction, hypertrophy), CXR, Serum urea, creatinine and electrolyte to check renal function, FBC, LFTs (albumin, protein), beside echocardiography.
T: Treat HF/AKI, be cautious with IV fluids

Question 32

Gynaecomastia

Answer 32

Enlargement of the male breast tissue - the presence of >2 cm of palpable, firm, subareolar gland and ductal breast tissue.
C: Increased age, lack of testosterone, increased oestrogen, medication (oestrogen, digoxin, inhibitors of testosterone synthesis), T1 diabetes, chronic illness, spinal cord injury.
S: Asymptomatic, breast enlargement, tenderness, sexual dysfunction.
D: LFTs, TFTs, hormonal profile, chromosomal karyotyping, ultrasonography or mammography of breasts, biopsy.
T: Treat the underlying problem, reassurance if no malignancy is found, tamoxifen for pain, subcutaneous mastectomy or liposuction associated mastectomy if chronic and no treatment found.

Question 33

Galactorrhoea

Answer 33

Milky secretion from the breasts not due to breastfeeding. Can be spontaneous or expressed.
C: Post-lactation, nipple stimulation, idiopathic, prolactinomas, hypersecretion of prolactin, drugs, chronic kidney disease, liver failure, hypothyroidism, epileptic seizures, chest wall lesions, pituitary stalk infiltration or interruption,
S: Production of milky discharge, hyperprolactinaemia (acne, hirsutism, menstrual irregularity, reduced libido, infertility and erectile dysfunction), signs of hypothyroidism, acromegaly, Cushing’s, signs of pitituary tumours (headaches, visual symptoms, cranial nerve symptoms).
D: Prolactin levels, TFTs, renal, LFTs, cranial nerve exam, MRI
T: Treat underlying hyperprolactinemia and hypothyroidism, review medication, dopamine agonists such as bromocriptine or cabergoline, hormone treatment.

Question 34

Lactose intolerance

Answer 34

Deficiency in lactase, which would otherwise hydrolyse lactose in milk to the monosaccharides, glucose and galactose.
C: Primary (genetic - autosomal recessive, at any age), Secondary (due to damage to the intestinal mucosa), Congenital (genetic - autosomal recessive, at birth, minimal or complete loss of lactase), Developmental (due to immature intestines).
S: Bloating, flatulence, abdominal discomfort, loose watery stool, perianal itching due to acidic stools.
D: Clinical features, lactose tolerance test, breath hydrogen test, genetic tests, intestinal mucosal biopsy obtained by endoscopy.
T: Trial of 2 week lactose-free diet, then reintroduction of lactose, identify what they can tolerate, lactase enzyme preparations, IV rehydration may be needed in secondary lactase deficiency

Question 35

Phaeochromocytoma

Answer 35

A rare tumour that secretes catecholamines. It is derived from chromaffin cells, usually in the adrenal medulla.
C: Sporadic or familial (genetic predisposition)
S: Headache, profuse sweating, palpitations, tremor, nausea, weakness, anxiety, sense of doom, epigastric and flank pain, constipation, weight loss, fever, hypertension.
D: Blood glucose (often raised), calcium levels (often raised), Hb (often raised), plasma catecholamines and plasma metanephrines levels, 24 hour urine collection for creatinine, genetic testing, CT/MRI for metastasis.
T: Surgical resection, control of hypertension (alpha and beta blockers, calcium channel blockers), after surgery, a 24-hour urine collection for total catecholamines, metanephrines and VMA is required two weeks after operation.

Question 36

Carcinoid tumours

Answer 36

Rare, slow-growing tumours that originate in cells of the diffuse neuroendocrine system, usually in tissues derived from the embryonic gut.
C: Sporadic mutations, risk factors include age, being a woman, family history.
S: Pain, weight loss, palpable mass, right-sided abdominal discomfort, endocardial or retroperitoneal fibrosis, hypoalbuminaemia, pellagra.
Carcinoid syndrome can occur alongside, it presents with flushing, diarrhoea, abdominal pain, palpitations, hypotension and wheezing.
D: Plasma chromogranin A,
24-hour urinary excretion of 5-hydroxyindoleacetic acid, FBC, LFTs, TFTs, parathyroid hormone, calcium, calcitonin, prolactin. alpha-fetoprotein, carcinoembryonic antigen, beta-hCG, endoscopy, CT/MRI.
T: Avoid precipitating factors, surgical resection, Somatostatin analogues for nonresectable tumours, Interferon alfa is a useful additive therapy, External beam radiotherapy may relieve bone pain from metastases.