Figure 3.
Light microscopy and immunohistochemistry. (A) H&E, 20×. Polypoid submucosal mass. 0.7 × 0.6 × 0.5 cm, proximal sigmoid, completely excised. (B) H&E, 100×. Sheets of plasma cells and 2 residual germinal centers within the lamina propria. (C) H&E, 200×. Sheets of plasma cells. (D) CD138 (IHC) highlights sheets of plasma cells. (E and F) Kappa and lambda light chains (IHC) demonstrate kappa restriction. H&E, hematoxylin and eosin; IHC, immunohistochemistry.