21st June 2023

Diagnosis

Tumour lysis syndrome (TLS) is a serious and potentially preventable oncological emergency which carries a profound risk of morbidity and mortality. The underlying mechanism is massive tumour cell lysis, typically seen in highly chemosensitive or bulky cancers in response to systemic anticancer therapy. The resulting cell breakdown causes the release of intracellular contents including nuclear material. Nucleic acids are broken down into uric acid, which precipitates in the renal tubules, causing severe acute kidney injury. Alongside this, large volumes of potassium and phosphate are released into circulation. In the presence of hyperphosphataemia, calcium is lost from the circulating volume as calcium phosphate precipitates in the renal tubules.

The Cairo-Bishop definition of biochemical TLS is any two of the following:

• Uric acid: >476 µmol/L
• K⁺: >6.0 mmol/L
• PO₄³⁻: >2.1 mmol/L
• Ca²⁺: <1.75 mmol/L

Commonly associated malignancies include:

• High-grade non-Hodgkin’s lymphoma – particularly Burkitt’s lymphoma
• Acute lymphoblastic leukaemia
• Acute myeloid leukaemia
• Chronic lymphocytic leukaemia
• Small cell carcinoma – particularly of the lung
• Germ cell tumours