[Splenic irradiation as a successful treatment for an elderly patient with B-cell prolymphocytic leukemia].

We report a case of B-cell prolymphocytic leukemia (B-PLL) that was treated successfully with splenic irradiation (SI). An 86-year-old man underwent a medical examination for lumbago and general fatigue at another hospital in June 2007. A compressed lumbar fracture and splenomegaly were found using computed tomography (CT). Thereafter, the patient consulted our hospital because of leukocytosis. Peripheral blood showed hemoglobin level 9.8 g/dl and white blood cell count 38.1x10(9)/l with 91% atypical cells. Surface marker analysis demonstrated that atypical cells were positive for CD20, CD22, FMC7, surface IgM, surface IgD and kappa, but were negative for CD5, TdT and lambda. The morphology of these cells was compatible with prolymphocytes with prominent nucleoli and condensed nuclear chromatin. A diagnosis of B-PLL was made. SI (total dose 20 Gy) was chosen for the treatment and a single course of SI was very effective without causing any significant adverse events. This case demonstrates that SI may remain valuable for the treatment of B-PLL in an elderly patient.