A 7-year-old boy presented to the hematology–oncology clinic for treatment of severe aplastic anemia. He received immunosuppressive therapy that included horse antithymocyte globulin, followed by oral cyclosporine. Several months after cyclosporine therapy was started, gum hypertrophy developed. The patient was subsequently weaned from cyclosporine, and the gum hypertrophy resolved. Two years later, the patient had disease recurrence and received a second course of treatment with horse antithymocyte globulin, followed by oral cyclosporine. After several months of cyclosporine therapy, gum hypertrophy developed again and progressed in severity to the extent that, about a year after the start of therapy, hypertrophic gum tissue completely covered his upper incisors (image). He also had growth of facial hair (hirsutism is another known side effect of cyclosporine). Despite the gum hypertrophy, he had no problems chewing food. The patient is no longer receiving cyclosporine therapy, and the gum hypertrophy has again resolved. Bina S. Menon, M.R.C.P. Kok-Hoi Teh, M.R.C.P.C.H. Hospital Kuala Lumpur, Kuala Lumpur, Malaysia Source: nejm.org