eng Science and Education Publishing American Journal of Cancer Prevention 2328-7314 2015-02-10 3 1 1 3 10.12691/ajcp-3-1-1 AJCP2015311 article Mehrdad Payandeh 1 Masoud Sadeghi sadeghi_mbrc@yahoo.com 2 Edris Sadeghi 3 Seyed Hamid Madani 4 Department of Hematology and Oncology, Kermanshah University of Medical Sciences, Kermanshah, Iran Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran Department of Nursing, Kermanshah University of Medical Sciences, Kermanshah, Iran Molecular Pathology Research Center, Imam Reza Hospital, Kermanshah University of Medical Sciences, Kermanshah, Iran Richter transformation is defined as a diffuse large cell lymphoma, occurring by transformation of chronic lymphocytic leukemia (CLL) and diffuse large B-cell lymphoma (DLBCL) is the most common type of richter syndrome. Herein, we describe report of a 51 year-old man in western Iran that referred to Hematology Clinic with complaint of three months of weight loss and sweating with generalized abdominal lymphadenopathy and the Bulky cervical lymph node. Pathology's specimens for him demonstrated CLL in the patient (Rai system stage 4) and during seven years ago, he was treated with fludarabine and cyclophosphamide regiment for 6 courses. Cervical biopsy pathology reported a new diagnosis of diffuse large B-Cell lymphoma and also immunohistochemistry (IHC) analysis showed CD3, CD20, CD45 were positive and Bcl-2 was negative and so he was treated with new regiment of R-CHOP for 6 courses. One month after last course of chemotherapy, Cerebrospinal fluid cytology was positive with lymphomatous involvement, and also brain CT SCAN showed parenchymal involvement and therapy with high dose Methotrexate began for him. The result is that specialists should be careful that probably fludarabin therapy alone or combination it with other drug especially cyclophosphamide can effect on transformation CLL to DLBCL. http://pubs.sciepub.com/ajcp/3/1/1/ajcp-3-1-1.pdf Cyclophosphamide Fludarabine Lymphoma Richter Syndrome