B-LBL arising out of CNL. The peripheral smear demonstrates circulating blasts with single to multiple prominent nucleoli (A; original magnification ×600; Wright's stain). The bone marrow biopsy is markedly hypercellular with an increase in blasts (B; original magnification ×600; hematoxylin and eosin stain). By immunohistochemistry, the blasts coexpress CD79a (C; original magnification ×600) and CD34 (D; original magnification ×600).