[Cutaneous large B-cell leg-type lymphoma occurring on a leg burn].

BACKGROUND: Primary cutaneous B-cell lymphomas form a heterogeneous group of lymphoid proliferations found on the skin. We report a case of primary leg-type cutaneous large B-cell lymphoma occurring on the site a previous leg burn. A few rare cases of cutaneous lymphoma forming on burn scars have been described, but these concern primary cutaneous lymphomas of the T-cell phenotype. CASE REPORT: An 85-year-old man with a history of a burn to the left leg 17 years ago, previously treated with several skin grafts, presented numerous ulcerative budding lesions on the scar area. Histological examination of the skin biopsy revealed the existence in the skin ulcers of atypical large lymphoid cells having an immunoblastic or centroblastic morphology and shown by immunohistochemistry to be of the B-cell phenotype, thereby evoking a diagnosis of large B-cell lymphoma. The lymphoma cells were positive for MUM1/IRF4 and BCL2, and more weakly for BCL6, but negative for CD10. The staging examination revealed only cortical lysis of the left tibia. Temporary initial regression was achieved by polychemotherapy comprising cyclophosphamide, vincristine and prednisone in combination with rituximab. DISCUSSION: This case is novel in that it involves primary large B-cell lymphoma, leg type, occurring on burn scar tissue. Venous insufficiency and lymphatic stasis have already been incriminated in the genesis of this type of lymphoma; the prior injury and resulting immune dysregulation at the burn site may have also contributed to the development of this neoplasia.