Rapidly progressive stage IVB mycosis fungoides treated with low-dose total skin electron beam therapy

Mycosis fungoides (MF) is the most common subtype of primary cutaneous T-cell lymphoma. Normally, MF has an indolent course although patients can progress to an advanced disease state (stages IIB-IVB). Advanced-stage disease is typically aggressive, leaving patients with debilitating symptoms and a decreased quality of life. Moreover, advanced-stage MF often proves refractory to therapy and carries a very poor prognosis. Total skin electron beam (TSEB) therapy is a well-established and successful treatment for early stage MF; however, its efficacy dramatically decreases with advanced-stage disease. In fact, TSEB in advanced-stage MF is generally considered to be palliative. Current consensus guidelines recommend a dose of 30-36 Gy to be delivered in 8-10 weeks; however, limited studies exist to determine the ideal treatment in Stage IV MF. Herein, we describe a case of a 50-year-old male who developed rapidly progressive stage IVB (T3N3M1B0) MF and was treated with low-dose (24 Gy) TSEB over 8 weeks. The patient was not treated with any systemic therapy before starting TSEB due to the widespread nature and the speed of disease progression. Remarkably, our patient showed nearly complete (95%) response of his MF with no apparent side effects from radiation. Furthermore, he has remained in remission over 4 years, requiring only a small boost to a few "shadowed" areas. Our case illustrates the benefit of using TSEB in stage IV MF. Additionally, our experience shows that low-dose TSEB can occasionally be efficacious in stage IV disease.