Tumour Lysis Syndrome

Question 1

Definition

Answer 1

A group of metabolic abnormalities that can occur as a complication during treatment of cancer, where large amounts of tumour cells are lysed at the same time by treatment, releasing their contents into the bloodstream.

Question 2

Aetiology

Answer 2

· It is caused by the sudden lysis of many tumour cells, which release their toxic contents into the blood stream

· Occurs most commonly after treatment of lymphomas and leukaemias

Question 3

Risk factors

Answer 3

o Tumour Characteristics - high cell turnover rate, rapid growth rate, high tumour bulk

o Patient Characteristics - baseline serum creatinine, renal insufficiency, dehydration

o Chemotherapy Characteristics - chemo-sensitive tumours (e.g. lymphoma) tends to have a higher risk

Question 4

Epidemiology

Answer 4

Tends to occur most commonly in patients with poorly differentiated lymphomas and leukaemias

Question 5

Presenting symptoms

Answer 5

· Hyperkalaemia
o K+ is mainly an intracellular ion
o Symptoms:
· Arrhythmias
· Severe muscle weakness and paralysis

· Hyperphosphataemia
o Causes acute kidney failure because of deposition of calcium phosphate crystals in the kidney parenchyma

· Hypocalcaemia
o Calcium precipitates to form calcium phosphate, so serum calcium drops
o Symptoms:
· Tetany
· Parkinsonism
· Myopathy
· Sudden mental incapacity

· Hyperuricaemia
o Leads to gout

· Lactic Acidosis

Question 6

Investigations

Answer 6

· Check the levels of all the metabolites that are deranged:
o Potassium
o Phosphate
o Calcium
o Uric acid

· Monitor for symptoms:
o Increased serum creatinine
o Arrhythmia
o Seizure