Eradication of Borrelia burgdorferi infection in primary marginal zone B-cell lymphoma of the skin

Extranodal lymphoma of MALT-type: perspective at the beginning of the 21st century

Extranodal lymphomas arising from mucosa associated lymphoid tissue (MALT) have become a focus of interest in recent years due to their unique pathological and clinical properties. The link between Helicobacter pylori and the development of gastric MALT-type lymphoma has revolutionized treatment options as up to 80% of patients with early gastric MALT-type lymphoma achieve complete remission of the tumor following eradication of H. pylori. As opposed to surgical intervention, which has been the preferred form of treatment in the past, organ conserving approaches are increasingly being applied, as both irradiation and chemotherapy have given excellent results. However, mature data from prospective, randomized studies taking into account the concept of MALT lymphoma as a distinct entity are still lacking in order to define the optimal approach to the management of MALT-type lymphoma.

Lyme disease in central Europe

Lyme borreliosis is a fascinating disease, the aetiopathology of which is not yet completely known. Different subspecies of Borrelia burgdorferi sensu lato are responsible for the variable clinical course of the disease. Some new cutaneous (alopecia) and ocular (photophobia and retinal vasculitis) manisfestations have been described and the largest prospective study on erythema migrans during pregnancy was published during the last year. Optimal therapy of Lyme borreliosis is still lacking, but doxycycline, amoxicillin, penicillin, and ceftriaxone are recommended most frequently.

Cells of the marginal zone--origins, function and neoplasia

Splenic marginal zone B cells of humans and mice are anatomically positioned with specialized macrophages, dendritic and endothelial cells. Together, they function as the first line of defense against blood borne pathogens with a low triggering threshold for B cells providing a rapid proliferative and antibody response to infections. In humans, B cells with similar cytology and physical relations to follicles are found in lymph nodes and Peyer's patches. However, they also develop in mucosa-associated lymphoid tissue (MALT) and other sites, such as the thyroid and salivary gland, that normally lack organized lymphoid tissue. Chronic antigenic stimulation at these sites or in response to infection with Hepatitis C provides the milieu for mutations at FAS, API2/ML, TP53 and INK4a/p19ARF and the development of marginal zone lymphomas (MZL) in node, spleen and MALT. Only splenic MZL are seen in mice. A reduced threshold for triggering to proliferation may predispose the marginal zone B cell to neoplasia with mutations in genes regulating apoptosis playing a leading role.

MALT Lymphomas

This review addresses the biology and the treatment of lymphomas arising from mucosa-associated lymphoid tissue (MALT). This entity, first described in 1983, represents about 8% of all non-Hodgkin's lymphomas and was recently re-classified as "extranodal marginal zone lymphomas of MALT-type." The term marginal zone lymphoma (MZL) encompasses the three closely related lymphoma subtypes of nodal, primary splenic and extranodal lymphomas of MALT type: the latter represent the vast majority of MZL. These lymphomas arise at different anatomic sites, are composed of mature B-cells lacking expression of CD5 and CD10, often present with overlapping morphologic features, but typically quite distinct clinical behaviors. Only very recently cytogenetic/molecular genetic observations have underlined the distinctiveness of these three lymphoid neoplasms, which in both the R.E.A.L. and WHO-classifications are included in the general term of MZL. MALT lymphomas arise in numerous extranodal sites, but gastric MALT lymphoma is the most common and best studied and is, therefore, the paradigm for the group as a whole. Dr. Isaacson describes the principal histological features of these lymphomas, including criteria to distinguish this entity from other small B-cell lymphomas. Several lines of evidence suggest that gastric lymphoma arises from MALT acquired as the result of aH. pyloriinfection. However, at least 1/3 of cases do not respond to eradication ofH. pylori. Very recent data suggest that both t(11;18) (q21;q21) and bcl10 nuclear expression are associated with failure to respond to this treatment. Dr. Gascoyne discusses the biologic function of proteins deregulated through the different translocations, which play a role in pathogenesis of MALT lymphomas, emphasizing particularly their influence in disrupting the apoptotic pathway. Dr. Zucca reviews findings suggesting that MALT lymphoma is an antigen driven neoplasm. He also presents specific guidelines for treatment of gastric lymphomas trying to shed some light on the amazingly inconsistent and confusing data in the literature. Taking advantage on the more than 300 non-gastric MALT lymphomas collected by the International Extranodal Lymphoma Study Group (ILESG), Dr. Cavalli compares gastric lymphomas with those arising in many other sites. Overall, the data presented in this session will underline the fact, that MALT lymphomas are characterized by some unique biological properties.

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. burgdorferi 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.

Primary cutaneous lymphomas

Primary cutaneous lymphomas have a distinct clinical behavior and prognosis, and therefore require a different therapeutic approach, as compared with their primary nodal equivalents. The European Organization for Research and Treatment of Cancer (EORTC) classification for primary cutaneous lymphomas recognizes a limited number of cutaneous T-cell lymphomas and cutaneous B-cell lymphomas and is at present the best guide to optimal management and treatment of these conditions. Herein, the relationship between the EORTC classification and the recently published World Health Organization classification is discussed, and recent developments regarding the main types of cutaneous T-cell lymphomas and cutaneous B-cell lymphomas recognized in the EORTC classification are presented.