Lymph node hyperplasia. Light micrograph of a section through a lymph node showing paracortical hyperplasia. Hyperplasia is the abnormal proliferation of cells. Damage or inflammation in any tissue may cause a reactive response in the lymphoreticular cells of lymph nodes that drain the affected area. In paracortical (parafollicular) hyperplasia the lymphoid follicles (less dense area, top) are small and often pushed to the periphery by the mass of proliferating lymphocytes (white blood cells) in the paracortical zone (dark area). This form of hyperplasia is often seen in viral infections.