Question

A 36-year-old woman with symmetrical small joint arthritis tests positive for anti-CCP. Which histological feature is most characteristic?

• A. Synovial granulomas
• B. Pannus formation and reactive lymphocytic infiltrate
• C. Uric acid crystal deposits
• D. Non-caseating granulomas

Hint:

Anti-CCP positive symmetrical small joint arthritis = rheumatoid arthritis; histology shows pannus formation.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The clinical triad of symmetrical small joint arthritis, female gender, and Anti-CCP positivity is diagnostic of Rheumatoid Arthritis (RA). We need to find its characteristic histological feature.
Step 2: Detailed Explanation:

Definition of Pannus: The hallmark histological feature of RA is the "Pannus." This is an abnormal layer of fibrovascular tissue or reactive granulation tissue composed of proliferating synovial cells, lymphocytes, plasma cells, and fibroblasts.

Mechanism of Damage: The pannus originates from the synovium and invades the articular cartilage. It releases proteolytic enzymes (like collagenases) that destroy the cartilage and underlying bone, leading to joint erosions.

Lymphocytic Infiltrate: The synovium in RA shows intense infiltration by T-cells and B-cells, often forming organized lymphoid follicles.

Anti-CCP: This antibody is highly specific for RA and is associated with more aggressive disease and extensive pannus formation.
- Uric acid (C): Hallmark of Gout.
- Non-caseating granulomas (D): Hallmark of Sarcoidosis.

Step 3: Final Answer:
Pannus formation is the defining pathological process that causes joint destruction in Rheumatoid Arthritis.