[Non-Hodgkin's lymphoma and pustular psoriasis: a case report].

Psoriasis has been hypothesized to be associated with lymphoma. Several studies demonstrated an epidemiological relationship between these two entities. Patients with psoriasis are at increased risk for developing lymphoproliferative malignancies. This risk can be also the consequence of immunosuppressive therapies (methotrexate or cyclosporine). We report a 65-year-old man who presented with diffuse erythematous plaques with pustular or squamous borders. Histopathologic evaluation concluded to a pustular psoriasis. We discover simultaneously a stage 4 bone marrow B lymphoma of low grade of malignancy. This case report highlights the relationships between psoriasis and lymphoma.