SPN and neoplasm: Immunohistochemical analysis showed the following characteristics of the tumor cells: cytokine (CK, −), cluster of differentiation (CD) 45 (weak +), CD20 ( −), CD3 ( −), CD5 ( −), CD34 (partial tumor cells +), CD43 (partially weak +), CD117 ( −), myeloperoxidase (MPO, +), e-cadherin ( −), CD10 ( −), CD15 ( −), CD163 ( −), CD235a ( −), CD61 ( −), CD138 ( −), anaplastic lymphoma kinase ( −), CD21 ( +) (Fig. 7), CD23 ( −), CD35 ( +) (Fig. 8), CD68 ( −), langerin ( −), S-100 ( −), smooth muscle actin (SMA, −), and Ki-67 (approximately 50% +) (Fig. 9).