Rheumatoid nodule



A rheumatoid nodule is a collection of normal cells including lymphocytes, and fibroblasts that surround a center of fibrinoid necrosis. They are usually subcutaneous especially over boney prominences such in the olecranon. About 5% of rheumatoid arthritis patients have such nodules within 2 years of disease onset, and the cumulative prevalence is about 25%.