Fig. 2

a The cut surface of the resected spleen, illustrating a solitary, round and dark-red mass with expansile growth compressing the surrounding parenchyma (10% buffered formalin-fixed). b Low-power view showing the lesion (right field) composed of unorganized sinusoid-like channels without malpighian corpuscles, less well demarcated from the adjacent normal splenic tissue (left field) (H&E, × 100). c In some areas, the cavernous vascular channels were filled with erythrocytes and foci of fat vacuoles can be noted (H&E, × 100). d-f Many bizarre large cells are scattered in the stroma throughout the lesion, with oval, reniform, multilobulated, or convoluted nuclei. The chromatin is pale, granular or vesicular. Sometimes nuclear grooves (e, arrow) are present. Note large cells (d, arrows) with double nuclei and apparent eosinophilic nucleoli mimicking Reed-Sternberg cells in classical Hodgkin’s lymphoma. (H&E, × 400)