A case of Richter's syndrome with transformation of B-CLL to DLBCL in the mandibular condyle region

We encountered a very rare case involving a 67-year-old male with Richter's syndrome showing transformation of B-cell chronic lymphocytic leukemia (B-CLL) to diffuse large B-cell lymphoma (DLBCL) in the left mandibular condyle region. CLL had been diagnosed at another hospital 9 years before visiting our hospital. He had not received positive treatment for CLL. Local examination revealed a mass in the left preauricular region. Histological and immunohistological examination of biopsy tissue from the left preauricular region revealed infiltration of DLBCL, in this case caused by transformation of B-CLL. We diagnosed Richter's syndrome with transformation of B-CLL to DLBCL. Although local irradiation was performed and intravenous cyclophosphamide, vincristine, doxorubicin, and prednisone were administered, the patient died 12 months after diagnosis of Richter's syndrome.