From the Guidelines
To rule out tumor lysis syndrome (TLS), one should order a comprehensive metabolic panel including serum electrolytes (potassium, phosphorus, calcium), renal function tests (BUN, creatinine), uric acid levels, and LDH, as recommended by the consensus conference on the management of tumor lysis syndrome 1. These laboratory tests are essential because TLS is characterized by specific metabolic abnormalities that occur when large numbers of cancer cells rapidly break down, releasing their intracellular contents into the bloodstream. Typically, TLS presents with:
- Hyperkalemia
- Hyperphosphatemia
- Hypocalcemia
- Hyperuricemia
- Acute kidney injury A complete blood count should also be ordered to assess the underlying malignancy, as suggested in the workup for patients with acute lymphoblastic leukemia 1. Urinalysis can help evaluate for uric acid crystals and assess renal involvement. These tests should be ordered urgently in high-risk patients (those with high-burden hematologic malignancies or solid tumors undergoing cytotoxic therapy) and repeated frequently (every 4-6 hours initially) to monitor for developing abnormalities, as recommended by the consensus conference on the management of tumor lysis syndrome 1. Early detection through these laboratory tests allows for prompt intervention with hydration, allopurinol or rasburicase, and electrolyte management to prevent serious complications like renal failure and cardiac arrhythmias. The initial workup for patients with ALL should include a thorough medical history and physical examination, along with laboratory and imaging studies (where applicable), including a tumor lysis syndrome (TLS) panel 1. In patients at high risk of TLS, levels of LDH, uric acid, sodium, potassium, creatinine, BUN, phosphorus, and calcium should be monitored every 12 hours for the first three days, and every 24 hours subsequently, as recommended by the consensus conference on the management of tumor lysis syndrome 1.
From the Research
Laboratory Tests for Tumor Lysis Syndrome
To rule out tumor lysis syndrome (TLS), the following laboratory tests should be ordered:
- Electrolyte panel to check for:
- Uric acid level to check for hyperuricemia (elevated uric acid levels) 2, 3, 4
- Renal function tests, such as creatinine and blood urea nitrogen (BUN), to assess for acute kidney injury 2, 4
Rationale for Laboratory Tests
These laboratory tests are essential for diagnosing TLS, as they help identify the characteristic tetrad of hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia 3. Additionally, monitoring renal function is crucial, as TLS can lead to acute kidney injury 2, 4.
Note on Irrelevant Studies
Study 5 is not relevant to the diagnosis or management of tumor lysis syndrome, as it discusses precipitating antibodies in sera of normal blood donors against certain antigens related to type III allergy.