Figure 1.

Morphological features of the samples. (A) A uniform population of plasma cells with abundant cytoplasm, round eccentrally located nuclei and clock-face chromatin without nucleoli is observed. (B) A small percentage of tumor cells are EBER-positive. (C) Neoplastic population is characterized by monoclonal IGHV rearrangement. (D) Histological specimen shows a diffuse and cohesive proliferation of round- to oval-shaped large cells with scant cytoplasm, and prominent nucleoli. (E) EBER positivity is observed in 90% of the neoplastic cells. (F) The same IGHV rearrangement of the plasmacytoma samples is shown. (G) EBNA1, and (H) Ea-D and (I) Ea-R expression in blastic cells of the plasmablastic lymphoma sample is present. [A, D: Haematoxylin and Eosin; B, E: EBER in situ hybridization; G: EBNA1 stain; H: Ea-D stain; I: Ea-R stain. A-B, D–E, G–I: original magnification: 20×].