Figure 2.
![Histopathology of an EMP infiltrating the tonsil (patient 3). (A-B) An interfollicular expansion of CD20– (original magnification [om] ×25) (A) and IgA+ plasma cells (om ×25) (B) is seen. CD20 highlights B-cell follicles, which are in part attenuated. (C-D) Interfollicular areas contain sheets of mature plasma cells (hematoxylin and eosin; C, om ×100; D, om ×400). (E-F) The plasma cells are monotypic and express κ (om ×400) (E) but remain negative for λ light chain (om ×400) (F).](https://ash.silverchair-cdn.com/ash/content_public/journal/bloodadvances/9/15/10.1182_bloodadvances.2025016596/1/blooda_adv-2025-016596-gr2.jpeg?Expires=1757134561&Signature=i5XiNg7QwNnkWi5UWb9YAWvO4zp01-xN-TGk68xfkM8g6WN-fyt~slAPDu1eZcZNdWtf2SqFIcIqUsm-6RNfe8pn-VcrAtcHY7AsHZdmtefRtXmcCpBwye1sw3djDYcNgykjdiU6E6udOffFQ7l6fR4OP5UAKBMZPFxoULi0KBR30d9Qs5zKU2v~Upm4k4O7H1tOYgs7WPbN9OTaRRxpjfyvZV9qXpU6QhpYvKvuB2fr~H56mFsPNb2xJKCGFgVRO5DaPgmQ-49r4txutFFUh0zSyVCDU2lS2mZtp-AdYFgfi8vtf9aYLsKq3Tymvj42pDAUikgUVefn~K1Yvt~~~w__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Histopathology of an EMP infiltrating the tonsil (patient 3). (A-B) An interfollicular expansion of CD20– (original magnification [om] ×25) (A) and IgA+ plasma cells (om ×25) (B) is seen. CD20 highlights B-cell follicles, which are in part attenuated. (C-D) Interfollicular areas contain sheets of mature plasma cells (hematoxylin and eosin; C, om ×100; D, om ×400). (E-F) The plasma cells are monotypic and express κ (om ×400) (E) but remain negative for λ light chain (om ×400) (F).
