**Core Concept**
Gouty arthritis is a form of inflammatory arthritis caused by the deposition of monosodium urate (MSU) crystals within the synovial fluid of joints. This results from an excess of uric acid in the body, which can occur due to increased production, decreased excretion, or a combination of both.

**Why the Correct Answer is Right**
The correct answer is related to the presence of MSU crystals in the synovial fluid. When gouty arthritis is suspected, synovial fluid aspiration and examination under polarized light microscopy are essential diagnostic tools. The presence of needle-shaped, negatively birefringent MSU crystals within the synovial fluid confirms the diagnosis of gout. The MSU crystals are formed when uric acid levels exceed the solubility limit in the blood, leading to their deposition in joints.

**Why Each Wrong Option is Incorrect**
**Option A:** Not relevant to gouty arthritis, as it is a common finding in various inflammatory conditions.
**Option B:** Not specific to gouty arthritis, as it can be seen in other forms of arthritis, such as septic arthritis.
**Option C:** Not specific to gouty arthritis, as it can be seen in other forms of arthritis, such as rheumatoid arthritis.

**Clinical Pearl / High-Yield Fact**
Gouty arthritis is characterized by the deposition of MSU crystals within the synovial fluid, which can be confirmed by polarized light microscopy. This is a crucial diagnostic tool for differentiating gout from other forms of inflammatory arthritis.

**Correct Answer: C. Leukocyte count of 50,000-100,000 cells/mm^3 with a predominance of neutrophils, along with the presence of negatively birefringent MSU crystals.**