## **Core Concept**
Tumor lysis syndrome (TLS) is a life-threatening complication that occurs when a large number of cancer cells die rapidly, releasing their contents into the bloodstream. This leads to several metabolic abnormalities.

## **Why the Correct Answer is Right**
The correct answer involves understanding the pathophysiological changes in TLS. TLS is characterized by:
- **Hyperphosphatemia**: The release of intracellular phosphate from lysed cancer cells leads to elevated serum phosphate levels.
- **Hypocalcemia**: High phosphate levels cause the formation of calcium phosphate crystals, which deposit in tissues, leading to decreased serum calcium levels.
- **Hyperkalemia**: Not listed but important; potassium release from cells can lead to cardiac arrhythmias.
- **Hyperuricemia**: Uric acid release from nucleic acid breakdown can lead to renal failure.

## **Why Each Wrong Option is Incorrect**
- **Option C: Alkalosis** - TLS typically leads to metabolic **acidosis** due to the release of organic and inorganic acids from lysed cells, not alkalosis.
- **Option D: Hypokalemia** - TLS usually results in **hyperkalemia** due to potassium release from lysed cells, not hypokalemia.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is to monitor and manage TLS early, especially in cancers with high cell turnover like leukemias and lymphomas. Aggressive hydration and the use of rasburicase (a recombinant urate oxidase) can help mitigate some of the effects.

## **Correct Answer:** B. a, b.