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-c ell 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 s ites 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 immun ohistochemically by a standard streptavidin-biotin-complex technique. Genot ypic studies were also undertaken using semi-nested polymerase chain reacti on (PCR) for immunoglobulin heavy chain gene rearrangement, and nested PCR for B. burdgorferi flagellin gene. Both patients presented with erythematou s skin lesions, biopsy of which showed dense perivascular infiltrates compr ising small T-lymphocytes and collections of B-blasts. Primary cutaneous ma rginal zone lymphoma (MZL) developed subsequently in both cases at the same site. PCR for B. burgdorferi flagellin gene was positive in the perivascul ar lymphocytic infiltrates and the succeeding lymphomas in both patients. Conclusions: These results show that, at least in some instances, PCBCL ari ses from chronically stimulated lymphoid tissue acquired in the skin in res ponse to B. burgdorferi infection. This may have significant therapeutic im plications and warrant further studies on the extent of this association.