**Core Concept**
Tumor lysis syndrome (TLS) is a life-threatening condition that occurs when a large number of cancer cells die rapidly, releasing their contents into the bloodstream. This leads to a series of metabolic disturbances, including electrolyte imbalances and the formation of uric acid crystals.

**Why the Correct Answer is Right**
The correct answer is a combination of symptoms, but the key feature of TLS is the rapid release of intracellular contents into the bloodstream. This leads to hyperuricemia due to the breakdown of nucleic acids into uric acid. Additionally, the release of potassium ions (K+) from the lysed cells causes hyperkalemia. The rapid breakdown of ATP also leads to hyperphosphatemia. Hyperkalemia and hyperphosphatemia can lead to hypocalcemia, not hypercalcemia, due to the formation of calcium-phosphate complexes.

*Option A:* Hyperuricemia is a correct feature of TLS, as it occurs due to the breakdown of nucleic acids into uric acid.
*Option B:* Hypercalcemia is incorrect, as TLS typically leads to hypocalcemia due to the formation of calcium-phosphate complexes.
*Option C:* Hyperphosphatemia is a correct feature of TLS, as it occurs due to the rapid release of intracellular contents into the bloodstream.
*Option D:* Hypematremia is incorrect, as TLS typically leads to hyperkalemia, hyperphosphatemia, and hyperuricemia, but not hyponatremia.

**Clinical Pearl / High-Yield Fact**
Remember the "5 Ps" of TLS: **P**oisoning of the kidneys by uric acid (hyperuricemia), **P**oisoning of the heart by potassium (hyperkalemia), **P**oisoning of the bones by phosphate (hyperphosphatemia), **P**oisoning of the lungs by calcium (hypocalcemia), and **P**oisoning of the brain by acidosis (metabolic acidosis).

**Correct Answer:** A, C, E