[Marginal zone B-cell lymphoma affecting the skin: histological and phenotypic study of 49 cases].

Background: No histological or clinical criteria allow distinction between primary cutaneous marginal zone B-cell lymphoma (MZL) and secondary cutaneous forms of systemic marginal zone B-cell lymphoma. Consequently, staging alone can indicate the origin of lymphoma. Lymphoma is considered as primary cutaneous only if no other extracutaneous sites are found. We studied the histological appearance of 49 cutaneous lymphomas in order to find distinctive criteria indicative of an extracutaneous origin.

Materials And Methods: This was a retrospective descriptive study of histological appearance for 49 patients with cutaneous marginal lymphoma: 29 cases of the primary form and 20 cases with extracutaneous involvement.

Results: Comparison of histological criteria did not reveal any differences between the primary cutaneous form and others forms. No prognostic criteria for relapse were found.

Discussion: A cutaneous tropism of primary MZL suggested the hypothesis of specific cutaneous receptors on B-cells that could have led to different histological appearances depending on the origin of the lymphoma. However, our study did not confirm this hypothesis.