Pyoderma Gangrenosum Associated with Multiple Myeloma: a Paraneoplastic Syndrome or Paradoxical Skin Reaction

The aim of this perspective article is to discuss the pathogenesis and treatment of pyoderma gangrenosum (PG), which can be seen as a paraneoplastic and/or drug-induced skin disorder in patients with multiple myeloma (MM). PG, a rare inflammatory neutrophilic dermatosis, may be idiopathic or associated with hematological malignancies at a rate of 3.9-45.6%. Among hematological malignancies, plasma cell dyscrasias (mostly IgA gammopathy) such as monoclonal gammopathy of undetermined significance and MM are the most frequently associated with PG. It is necessary to suspect and take place further investigations in terms of hematological malignancies including MM in cases of multifocal and recalcitrant ulcerative PG. Although conventional treatment in PG includes the use of immunosuppressive agents, PG may also occur in the presence of immunosuppression. Therefore, it should also be kept in mind that PG lesions may develop paradoxically when administering anti-myeloma treatments.