Introduction

The body has approximately 600 lymph nodes. Those in the submandibular, axillary, cervical or inguinal regions may often be palpable in healthy children - particularly if they are slender. Normal lymph nodes are soft, easily compressible and freely mobile. The spleen, tonsils, adenoids and Peyer patches are also part of the lymphatic system that filter antigens from the extracellular fluid. Lymph nodes may become enlarged for numerous causes including benign processes and more concerning pathology.

Lymphadenopathy (LAP) refers to nodes that are abnormal in either size, consistency or number. It may be one of the symptoms of many diseases. The history of the patient should be considered carefully because it may provide clues to the underlying diagnosis. In general, if a lymph node diameter exceeds one cm it is considered abnormal. There are exceptions in different regions and lymph nodes have different sizes at different ages [1].
The cervical region is the most commonly involved area among peripheral LAP. Generalized LAP usually indicates an underlying disease such as the Epstein-Barr virus, human immunodeficeincy virus, lymphoma or an autoimmune disorder.

In general, palpable supraclavicular, iliac, popliteal and epitrochlear nodes greater than 0.5 cm and inguinal nodes larger than 1.5 cm are abnormal [2].

content in this topic is references in SCORE Lymphadenopathy, Atypical Mycobacteria overview