LYMPHOMATOID PAPULOSIS - A CLINICAL AND HISTOPATHOLOGIC REVIEW OF 53 CASES WITH LEUKOCYTE IMMUNOPHENOTYPING, DNA FLOW-CYTOMETRY, AND T-CELL RECEPTOR GENE REARRANGEMENT STUDIES

Background: Lymphomatoid papulosis (LyP) is a recurrent hemorrhagic papular skin eruption with a clinically benign course and histopathologic features of lymphoma. Objective and Methods: To better characterize this disease, we studied 53 patients seen since 1965. Results: A lymphoproliferative malignancy developed within 2 to 36 years after onset of LyP in eight patients. Histologically, the dermis in LyP showed an infiltrate of large (type A) or small (type B) atypical lymphocytes. The large atypical cells (type A) stained with CD30 (Ber-H-2). Seven of the patients in whom lymphoma developed had type A histologic features. DNA flow cytometry showed mainly a diploid pattern, except for two cases that showed aneuploidy. Five of 11 patients showed T-cell receptor (TCR) clonal gene rearrangements; lymphoma has not developed in these patients. One patient had a TCR rearrangement in a plaque of mycosis fungoides but not in the LyP lesion. Conclusion: LyP is either a reactive skin condition or a localized lymphoid malignancy. Neither DNA flow cytometry nor TCR gene rearrangement can predict the 15% to 19% of patients in whom a lymphoma will develop. Continued observation of all patients is essential.