Figure 3.

Macroscopic (A) and histological (B-F) findings of the resected spleen in case 4. (A) Photograph of resected spleen weighing 574 gram; (B, C) Histological examination demonstrated splenic sinus congestion and decreased white pulp, with local extramedullary hematopoiesis (B: hematoxylin-eosin, x 40, C: hematoxylin-eosin, x 400); (D, E, F) Immunohistochemical studies revealed CD41-positive megakaryocytes (D, white arrowhead, x 400), CD71-positive erythroid lineage cells (E, x 200), and myeloperoxidase-positive myeloid lineage cells (F, x 200) in the spleen.