A rare case of the cutaneous form of adult T-cell leukaemia/lymphoma: assessment of remission by PCR for clonal T-cell receptor gamma gene rearrangements in an electron beam-irradiated cutaneous lesion.

Adult T-cell leukaemia/lymphoma is a lymphoproliferative disorder aetiologically associated with human T-cell lymphotropic virus type I infection. A cutaneous lesion often develops in the disease, and in rare cases, is even the only manifestation. Here we report a rare case of 'cutaneous' adult T-cell leukaemia/lymphoma with neither atypical cells in the peripheral blood nor lymph node involvement. All nodular lesions were completely eliminated after local electron beam irradiation (20 Gy/nodule in total). To evaluate whether or not there were residual lymphoma cells in the skin, we performed PCR to detect clonal T cell receptor gamma gene rearrangements. The sample from the nodule before irradiation showed evidence of a rearranged band, which was not detected at the same site after treatment nor in any peripheral blood. The findings suggest that this procedure is useful for the evaluation of therapeutic effects and the early detection of lymphoma recurrence.