Recent work has demonstrated that B-cell cutaneous lymphoid hyperplasia (BCCLH) lies in a spectrum of B-cell lymphoproliferative disorders that can progress to primary cutaneous B-cell lymphoma (CBCL). In light of this work, definitive therapy with methods such as radiotherapy is an important part of the treatment strategy. Few outcome data exist for patients with treatment-resistant BCCLH. We present a case study of a 63-year-old woman with BCCLH who failed immunomodulatory treatment but responded well to an aggressive course of radiotherapy. After 18 fractions of 6 MeV electron beam therapy with 200 cGy per fraction, the patient has been recurrence-free for 3 years. Acute toxicity was limited to Radiation Therapy Oncology Group grade II skin toxicity, which resolved within 1 month of treatment.