Borrelia burgdorferi-associated cutaneous marginal zone lymphoma:: a clinicopathological study of two cases illustrating the temporal progression of B-burgdorferi-associated B-cell proliferation in the skin

Aims: A relationship between Borrelia burgdorferi and primary cutaneous B-cell lymphoma (PCBCL) has recently been confirmed following demonstration of the organism in lesional skin of patients with PCBCL. We report herein two cases of B. burgdorferi-associated PCBCL which strengthen this association by demonstrating the organism in cutaneous B-cell infiltrates present at sites in which PCBCL subsequently developed. Methods and results: All studies were performed on formalin-fixed paraffin-embedded tissues. These were examined by routine light microscopy and immunohistochemically by a standard streptavidin-biotin-complex technique. Genotypic studies were also undertaken using semi-nested polymerase chain reaction (PCR) for immunoglobulin heavy chain gene rearrangement, and nested PCR for B. burdgorferi flagellin gene. Both patients presented with erythematous skin lesions, biopsy of which showed dense perivascular infiltrates comprising small T-lymphocytes and collections of B-blasts. Primary cutaneous marginal zone lymphoma (MZL) developed subsequently in both cases at the same site. PCR for B. burgdorferi flagellin gene was positive in the perivascular lymphocytic infiltrates and the succeeding lymphomas in both patients. Conclusions: These results show that, at least in some instances, PCBCL arises from chronically stimulated lymphoid tissue acquired in the skin in response to B. burgdorferi infection. This may have significant therapeutic implications and warrant further studies on the extent of this association.