Concomitant occurrence of kimura disease and mycosis fungoides in a Lebanese woman: significance and response to rituximab.

Kimura disease (KD) is a rare condition that predominantly affects young middle-aged Asian men. It is classically characterized by tumors in the head and neck region with associated eosinophilia and elevated serum immunoglobulin E levels. The exact pathogenesis of this condition remains unknown. Although some regard it as a reactive condition, others believe that it is a T-cell-mediated disease. T-cell clonality has been recently demonstrated in a few cases. We report a 37-year-old Lebanese woman who had both KD and mycosis fungoides (MF). T-cell receptor gene rearrangement studies using 2 different techniques did not detect any clonality for T-cell receptor in both KD and MF lesions. Due to the presence on histology of lymphoid follicles and the persistent high serum immunoglobulin E levels, we elected to attempt treatment with rituximab. Although the KD lesions persisted, they became softer and less nodular. As for the MF lesions, they flared transiently and then exhibited a sustained improvement over a follow-up period of 1 year.