Characterization of an interdigitating dendritic cell hyperplasia case in alymph node of a control C57BL/6 mouse

摘要

Interdigitating dendritic cell (IDC) hyperplasiais considered a benign spontaneous condition occasionally observed in the lymph nodes ofmice. It has been rarely reported and, to the best of our knowledge, it has never beencharacterized using immunohistochemistry. The present work describes a spontaneous IDChyperplasia case in a lymph node of a 16-week-old control female C57BL/6 mouse.Microscopically, the lymph node architecture was completely effaced by the proliferationof eosinophilic spindle cells with an abundant pale cytoplasm forming trabecule admixedlymphocyte infiltrates. The spindle cell population was positive for F4/80, partiallypositive for S100 calcium-binding protein A4 (S100A4), slightly positive for E-cadherin,and negative for α-Smooth muscle actin (SMA) and cytokeratin. Lymphocytes were positivefor CD3, CD4, CD20 and negative for CD8. Spindle cells were considered to be originatedfrom the myeloid lineage, based on the immunohistochemistry (IHC) results, but theirprecise origin remains unclear (IDC or macrophages); even if macrophage origin is mostlikely based on F4/80 positivity, this remains to be further clarified using othermarkers.