Secondary Lymphoid Tissues ›› Lymph Node ›› Non-neoplastic

Lymphadenitis (Non-neoplastic)*


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› Microscopic Features:

• Most do not show a completely effaced lymph node (as opposed to neoplastic processes such as lymphomas)
• The morphology can be variable based on the underlying disease
• Enlarged reactive secondary follicles are commonly seen
• Increased number of Immunoblasts are also commonly noted

› Normal % blood-PB, marrow-BM, lymphoid tissue-LN:

• PB: N/A
• BM: N/A
• LN: N/A

› May Resemble:

• Follicular Lymphoma [Compare]
• Non-neoplastic reactive Lymph node [Compare]
• Classical Hodgkin Lymphoma [Compare]

› Differential Diagnoses:

Drug-induced Autoimmune-induced Infection Neoplastic (e.g. Follicular lymphoma) Idiopathic (unknown cause)

› Classic Immunophenotype:

• "T"-cells have the "Tiny" CDs: CD2, CD3, CD4, CD5, CD7, CD8
• "B"-cells have the "Bigger" CDs: CD19, CD20, CD22

› Misc:

• Non-neoplastic lymphadenitis can be due to infection, drugs, autoimmune, or ideopathic