Curriculum · Hematology
Tumour lysis syndrome
What it is
Tumor lysis syndrome is the condition caused by cell lysis in a tumor that is being treated. It is seen in leukemias and high-grade lymphomas. Its electrolyte set is hyperkalemia, hyperphosphatemia and hypocalcemia, and uric acid rises with them.
Causes and risk
Two predisposing factors stand together: a highly proliferative malignancy, and the start of chemotherapy, which triggers the cell lysis. A newly diagnosed Burkitt's lymphoma commenced on chemotherapy is one, and induction chemotherapy for a newly diagnosed diffuse large B cell lymphoma (DLBCL) is another. In acute myeloid leukaemia it is one of three main complications, alongside leukostasis with hyperviscosity and DIC, the last of which carries a higher risk in APL.
What can go wrong
- Increased uric acid leads to nephropathy, gout and kidney stones
- Increased phosphate leads to decreased Ca and decreased Mg
- Increased potassium, released from damaged cells
The mechanism of the hypocalcemia is consumptive binding to phosphate: the high phosphate binds the calcium, so the calcium falls. Tumor lysis syndrome sits under the oncology causes of hypocalcemia that run with a high PTH, alongside vitamin D deficiency, chronic kidney disease, pancreatitis and sepsis.
Through increased uric acid production from high cell turnover it is also an etiology of gout, which is an inflammatory crystal arthropathy caused by the precipitation and deposition of uric acid crystals in synovial fluid and tissues.