CD25

CD25 is an IL-2 receptor.  CD25 is most often used as a marker for hairy cell leukemia, systemic mastocytosis, and adult T cell leukemia/lymphoma.  CD25 may stain activated B and T cells and cases of lymphoplasmacytic lymphoma (LPL).  CD25 is similar to CD30 in that it is an “activation” marker, and not specific.  Macrophages, and osteoblasts also often express CD25.
 
Non-neoplastic mast cells, marginal zone B cell lymphoma, T cell large granular leukemia/lymphoma, and variant hairy cell leukemia are usually negative for CD25.
CD25 Expression Pattern

Photomicrographs
CD25 expression in systemic mastocytosis.
CD25 expression in systemic mastocytosis.
CD25 expression in systemic mastocytosis.

References
Bone Marrow IHC.  Torlakovic, EE, et. al. American Society for Clinical Pathology Pathology Press © 2009.  pp. 75-76.
 
Diagnostic Immunohistochemistry:  Theranostic and Genomic Applications [edited by] David J. Dabbs. 3rd Edition.  pp. 165.
 
Lin, P., Molina, T. J., Cook, J. R., & Swerdlow, S. H. (2011). Lymphoplasmacytic lymphoma and other non-marginal zone lymphomas with plasmacytic differentiation. American Journal of Clinical Pathology, 136(2), 195–210. doi:10.1309/AJCP8FOIVTB6LBER
 
Karube, K., Suzumiya, J., Okamoto, M., Takeshita, M., Maeda, K., Sakaguchi, M., et al. (2007). Adult T-cell lymphoma/leukemia with angioimmunoblastic T-cell lymphomalike features: Report of 11 cases. The American Journal of Surgical Pathology, 31(2), 216–223. doi:10.1097/01.pas.0000213325.79368.2c
 
Siegert, S. I., Diebold, J., Ludolph-Hauser, D., & Löhrs, U. (2004). Are gastrointestinal mucosal mast cells increased in patients with systemic mastocytosis? American Journal of Clinical Pathology, 122(4), 560–565. doi:10.1309/2880-LF7Q-6XK3-HA3Q
 
Lin, P., & Medeiros, L. J. (2005). Lymphoplasmacytic lymphoma/waldenstrom macroglobulinemia: an evolving concept. Advances in Anatomic Advances in Anatomic Pathology, 12(5), 246–255.