Reactive lymph node conditions in childhood

Lymph node enlargement is a common manifestation of many childhood illnesses. Chronic lymphadenopathy lasting greater than 6 weeks or persistent enlargement of a single lymph node, regional lymph node group or systemic lymphadenopathy in the absence of an obvious cause are indications for lymph node biopsy or excision. In this review we cover common and less common causes of lymph node enlargement in childhood with their characteristic histological features. The most common morphological patterns, including follicular hyperplasia, interfollicular/paracortical expansion, sinus histiocytosis and granulomatous and necrotising lymphadenitis are discussed, with a description of features suggesting specific underlying aetiology and other adjuncts to precise diagnosis.