Lymphomatoid papulosis associated with mycosis fungoides: a study of 21 patients including analyses for clonality.

Background: Although an association of lymphomatoid papulosis (LyP) with mycosis fungoides (MF) is recognized, our understanding of this relation is limited.

Objective: We sought to document the clinical experience at the University of California, San Francisco, in 21 patients who had both LyP and MF and to do clonality studies in 7 of those patients in whom this was possible.

Methods: We conducted chart review of the 21 patients and analysis for T-cell receptor-gamma gene rearrangements by the polymerase chain reaction.

Results: Of 54 patients, 21 (39%) with LyP had associated MF. LyP preceded MF in 14 (67%), MF preceded LyP in 4 (19%), and there was concurrent appearance in 3 (14%). Of the 21 patients, 20 (95%) were type A and only 1 (5%) was type B. An identical clone was found in lesions of both LyP and MF in all 7 patients in whom analysis was possible.

Conclusion: Findings of this study strengthen the idea that LyP and MF are related T-cell lymphoproliferative disorders.