Coexistent cutaneous T-cell lymphoma and B-cell malignancy. French Study Group on Cutaneous Lymphomas.

Abstract

The coexistence of cutaneous T-cell lymphoma (CTCL) and a B-cell malignancy (BCM) is rare. Our aim was to assess the clinical and pathologic aspects of coexistent CTCL and BCM and to examine potential explanations for this association. We report six cases of concurrent CTCL and BCM in which B- and T-cell lineages were demonstrated by immunologic studies. The literature includes 13 additional cases. All 19 CTCL-BCM cases are reviewed. CTCL either preceded or followed the BCM, which was a low-grade malignancy in most cases (16 of 19). Possible explanations for the association include a genetic predisposition, underlying viral infection, chemotherapy-induced carcinogenesis, stimulation of a B-cell clone by malignant helper T cells, and alterations in progenitor cells before determination of B- and T-cell lineage. An alteration in progenitor cells, with subsequent oncogenic activation of variable origin, might account for most cases of coexistent CTCL and BCM.