Malignancy of the Lymph Node: How General Practitioners and Pathologists can achieve a Definitive Diagnosis

Abstract

The lymph node plays an important role in the lymphatic spread of abnormal antigens from exogenous or endogenous sources, including infectious agents, foreign bodies, self-antigens, and malignant cells, by harboring various immune cells that react to abnormal antigens and their sources. This often leads to enlargement of the lymph node, also known as “lymphadenopathy.” In this review article, malignancy of the lymph node is the main focus, especially regarding how general practitioners and pathologists can achieve a definitive diagnosis. The basic principle relies on the normal structure, cellular components, and functions of the lymph node as well as the types of malignancy found. Careful clinical history taking of any possible cause of lymphadenopathy warrants exclusion of any mimics of malignancy of the lymph node, including drug reactions and immunodeficiency states. An adequate cell or tissue sample allows pathologists to work efficiently by mastering the multimodality approach under good clinical collaboration. Effective communication between pathologists and physicians regarding relevant laboratory investigations should make it easier to diagnose a specific type of malignancy. This review article also focuses on how general pathologists handle cell or tissue samples by conventional morphologic evaluation and panels of immunohistochemistry so that general practitioners understand the diagnostic process and understand how to diagnose malignancy of the lymph node.