What effect does tumor lysis syndrome have on serum phosphate?

What effect does tumor lysis syndrome have on serum phosphate?

• A. Decreases
• B. Increases
• C. No effect
• D. Depends on kidney function

Answer: (B)

Tumor lysis syndrome causes rapid rupture of malignant cells, releasing intracellular contents into the bloodstream. Phosphate is abundant inside cells, so when cells lyse, phosphate floods into the circulation, leading to hyperphosphatemia. The kidneys try to excrete the excess, but the overall effect seen clinically is an increase in serum phosphate. The magnitude can be greater if kidney function is impaired, but the fundamental outcome is an elevated phosphate level. This rise in phosphate also contributes to hypocalcemia through calcium-phosphate precipitation.

Tumor lysis syndrome causes rapid rupture of malignant cells, releasing intracellular contents into the bloodstream. Phosphate is abundant inside cells, so when cells lyse, phosphate floods into the circulation, leading to hyperphosphatemia. The kidneys try to excrete the excess, but the overall effect seen clinically is an increase in serum phosphate. The magnitude can be greater if kidney function is impaired, but the fundamental outcome is an elevated phosphate level. This rise in phosphate also contributes to hypocalcemia through calcium-phosphate precipitation.