**Question:** Which is not seen in Tumor lysis Syndrome?

**Core Concept:** Tumor lysis syndrome (TLS) is a medical emergency characterized by the rapid release of cellular components into the bloodstream due to the death of rapidly dividing malignant cells. Clinical manifestations include hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and renal failure.

**Why the Correct Answer is Right:** Option C, "hypocalcemia," is not typically a feature of TLS. Hypocalcemia is a condition characterized by low blood calcium levels, which is usually seen in conditions like hypoparathyroidism or malabsorption syndromes. In TLS, the focus is on the elevated levels of uric acid, potassium, phosphate, and creatinine due to the rapid cell death and subsequent release of these substances into the bloodstream.

**Why Each Wrong Option is Incorrect:**

A. Hyperkalemia (elevated potassium levels) is a feature of TLS, as the rapid release of potassium from dying cancer cells contributes to the electrolyte imbalances seen in the syndrome.

B. Hyperuricemia (elevated uric acid levels) is also a feature of TLS, as the rapid release of uric acid from dying cancer cells leads to increased blood uric acid levels.

D. Hypophosphatemia (low phosphate levels) is often seen in TLS, due to the release of phosphate from the dying cancer cells into the bloodstream.

**Clinical Pearl:** The correct management of TLS involves aggressive hydration, alkalinization of urine, and treatment of electrolyte abnormalities to prevent kidney damage and acute kidney injury. Early recognition and intervention are crucial in managing TLS, as it can progress rapidly and lead to life-threatening complications.