Tumor Lysis Syndrome Workup

Updated: Oct 04, 2022
  • Author: Alan K Ikeda, MD; Chief Editor: Wafik S El-Deiry, MD, PhD  more...
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Approach Considerations

Early recognition of signs and symptoms of patients at risk for tumor lysis syndrome, including identification of abnormal clinical and laboratory values, can lead to successful prevention of the otherwise life-threatening complications of this condition.

In patients with tumor lysis syndrome, a sample of blood obtained by a wide-bore needle or, preferably, an indwelling cannula should be used to obtain a biochemical profile of the patient for monitoring, including of serum sodium, potassium, chloride, and bicarbonate.

Urine pH and output

If hyperuricemia develops, urine alkalinization prevents renal precipitation of uric acid but may increase the risk for nephrocalcinosis. If alkaline diuresis is employed, regular determinations of urine pH should guide the extent of therapy.

Because increased urine flow rates help to inhibit crystal deposition in renal tubules, close monitoring of urine output is necessary to assess adequacy of hydration. Monitoring urine output for signs of oliguric renal failure is also necessary.

Imaging studies

Radiography of the chest is useful to determine the presence of a large tumor (eg. mediastinal mass). Perform ultrasonography or computed tomography (CT) scanning of the abdomen and retroperitoneum immediately if renal failure or mass lesions in the abdomen are present. Intravenous (IV) contrast may be contraindicated in a patient with renal insufficiency.

Cardiac monitoring

Frequent cardiac assessment (electrocardiography [ECG] or continuous cardiac monitoring) is necessary to monitor electrocardiographic changes, which may herald a lethal arrhythmia caused by potassium and calcium disturbances.

Histologic findings

Pathologic studies demonstrate deposits of uric acid within the distal renal tubule lumina, which cause intrarenal hydronephrosis. Uric acid crystals can also be seen within tubular epithelial cells and the medullary microcirculation. Uric acid precipitates may also occur in the renal pelvis and ureters, leading to hydronephrosis and acute renal failure from extrarenal sources.


Blood Chemistry

High-risk patients should have laboratory monitoring (BUN, creatinine, phosphate, uric acid, and calcium levels) prior to therapy and for 48-72 hours after treatment induction. Follow measurements at least three times per day, or more often if evidence of tumor lysis syndrome develops. Lactate dehydrogenase should be checked at least on diagnosis and prior to treatment, as elevated values can reflect the potential for progressing to tumor lysis syndrome with the initiation of chemotherapy.

Most patients with tumor lysis syndrome have laboratory derangements in lactate dehydrogenase, potassium, phosphate, calcium, and uric acid, as well as abnormal renal functions, occurring 1-3 days after chemotherapy initiation. Hyperkalemia is often the first life-threatening abnormality.