Which electrolyte abnormality is commonly observed in tumor lysis syndrome?

Which electrolyte abnormality is commonly observed in tumor lysis syndrome?

• A. Hyperkalemia
• B. Hypokalemia
• C. Hyponatremia
• D. Hypercalcemia

Answer: (A)

Rapid tumor cell breakdown releases intracellular contents into the blood. Potassium is mostly inside cells, so when many tumor cells lyse, a large amount of potassium floods into the extracellular space, leading to hyperkalemia. This is an early, characteristic electrolyte change in tumor lysis syndrome and can cause dangerous ECG changes and arrhythmias if not treated promptly. Other shifts occur as well—phosphate and nucleic acids release can cause hyperphosphatemia and hyperuricemia, which promote calcium binding and result in hypocalcemia—but hyperkalemia best represents the classic electrolyte abnormality seen.

Rapid tumor cell breakdown releases intracellular contents into the blood. Potassium is mostly inside cells, so when many tumor cells lyse, a large amount of potassium floods into the extracellular space, leading to hyperkalemia. This is an early, characteristic electrolyte change in tumor lysis syndrome and can cause dangerous ECG changes and arrhythmias if not treated promptly. Other shifts occur as well—phosphate and nucleic acids release can cause hyperphosphatemia and hyperuricemia, which promote calcium binding and result in hypocalcemia—but hyperkalemia best represents the classic electrolyte abnormality seen.