Background: The coexistence of cutaneous T-cell lymphoma (CTCL) and a B-cell malignancy (BCM) is rare.
Objective: Our aim was to assess the clinical and pathologic aspects of coexistent CTCL and BCM and to examine potential explanations for this association.
Methods: 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.
Results: 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.
Conclusion: An alteration in progenitor cells, with subsequent oncogenic activation of variable origin, might account for most cases of coexistent CTCL and BCM.