Immune System
Lymph Node - Erythrophagocytosis
Narrative
Comment:
Erythrophagocytosis in lymph nodes consists of macrophages within sinuses that phagocytize extravasated, old, and/or damaged erythrocytes (Figure 1 and Figure 2, arrows). Erythrophagocytosis does not occur under normal conditions and is most often associated with lymph node hemorrhage, congestion, sinus erythrocytosis, and autoimmune and other immunopathologic conditions.
Recommendations:
When erythrophagocytosis is present within lymph nodes, it should be diagnosed and graded.
References:
Frith CH, Ward JM, Chandra M, Losco PE. 2000. Non-proliferative lesions of the hematopoietic system in rats. In: Guides for Toxicologic Pathology.TP/ARP/AFIP, Washington, DC.
Full Text: https://www.toxpath.org/docs/SSNDC/HematopoieticNonprolifRat.pdfNational Toxicology Program. 2011. NTP TR-561. Toxicology and Carcinogenesis Studies of Tetralin (CAS No. 119-64-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). NTP, Research Triangle Park, NC.
Abstract: https://ntp.niehs.nih.gov/go/33575
Lymph node - Erythrophagocytosis in a female F344/N rat from a chronic study. Numerous macrophages with intracytoplasmic erythrocytes (arrows) and extravasated erythrocytes fill the medullary sinus of this lymph node.
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Lymph node - Erythrophagocytosis in a female F344/N rat from a chronic study. Numerous macrophages with intracytoplasmic erythrocytes (arrows) and extravasated erythrocytes fill the medullary sinus of this lymph node.
Lymph node - Erythrophagocytosis in a female F344/N rat from a chronic study (higher magnification of Figure 1). Macrophages within the medullary sinus contain variable numbers of erythrocytes and/or pigment within their cytoplasm (arrows).