PAX5 and lymphoma: By immunohistochemistry, the lymphoma cells were positive for PAX‐5, CD5 (partial/weak) (Panel E: PAX‐5/CD5 dual stain, original magnification ×400), IgD (Panel F, original magnification ×400), DBA.44 (Panel G, original magnification ×400), and negative for Cyclin D1, SOX11, IgG, and BRAF V600E.