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Case 126 - Discussion

Hematopathology Case


This lymph node shows architectural effacement by many microabscesses. There are multiple extracellular amorphous pink materials, which are positive for Warthin-Starry staining, consistent with aggregates of bacteria.


Cat-Scratch Lymphadenitis

  • Necrotizing granulomatous lymphadenitis caused by Bartonella henselae

  • Healthy individuals -benign, self-limited illness, lasting 6-12 weeks without treatment; AIDS - disseminated or fatal

  • Micro:

    • Necrotizing granuloma

    • Central microabscesses with neutrophils

    • Peripheral palisaded epithelioid cells

    • Capsular and perinodal involvement

    • Clumps of extracellular pleomorphic bacillary bacteria, positive for Warthin-Starry silver stain

  • DDX:

    • Suppurative lymphadenitis: abscess formation with positive Gram's stain

    • Lymphogranuloma venereum: similar morphology, often impossible to differentiate, IFA and serology necessary. Morphologically, there are histiocytes with cytoplasmic vacuoles, which contain Chlamydia trachomatis L1, L2 and L3

    • Kikuchi necrotizing lymphadenitis: patchy paracortical lymphohistiocytic proliferation with necrosis, abundant nuclear debris, lack of neutrophils or epithelioid cells with granulomatous arrangement. C-shaped histiocytes and immunoblasts. Negative for Gram's stain or Warthin-Starry stain

Reference: Ioachim's Lymph Node Pathology, 4th edition