Chapter 10 - Benign lymph node

Abstract

The lymph system is an important part of body’s immune system, and lymph nodes, which are small bean-shaped glands and an integral part of lymph system, are located in clusters in various parts of the body including neck, armpit, and groin as well as inside the center of the chest and abdomen. A lymph node consists of cortex and medulla, encased in a fibrous capsule. Subcapsular sinus is located just underneath the capsule. Reactive lymphoid hyperplasia may be due to numerous causes, and the typical patterns of lymphoid hyperplasia are follicular hyperplasia, paracortical hyperplasia, sinusoidal expansion, granulomatous lymphadenitis, and mixed pattern. Infections are a common cause of both follicular and paracortical hyperplasia. Lymphadenopathy may be related to many reasons, and in this section, association of lymphadenopathy with certain specific diseases is addressed. Lymphadenitis, which refers to inflammation of lymph nodes, is often associated with lymphadenopathy, and it is often difficult to distinguish between two terms because these words may be used interchangeably.