Cutaneous plasmacytomas are monoclonal proliferations of plasma cells which can be classified into primary (with no other concomitant bony or extramedullary disease) or secondary (generally associated with multiple myeloma (MM), extramedullary plasmacytoma, or plasma cell leukemia). Cutaneous plasmacytomas can appear in some patients with MM and, rarely, the skin lesions suppose the first clinical manifestation of the disease. Their development is considered as a poor prognostic sign, associated with a life expectancy of less than 12 months after diagnosis. An unusual case of MM is described, in which the histopathological study of a skin nodule provided invaluable information for diagnosis.
Neutrophilic dermatoses (NDs) are a group of noninfectious disorders characterized by the presence of a sterile neutrophilic infiltrate without vasculitis histopathology. Their physiopathology is not fully understood. The association between neutrophilic dermatoses and autoinflammatory diseases has led some authors to propose that both are part of the same spectrum of diseases. The classification of NDs depends on clinical and histopathological features. This review focuses on the recent developments of treatments in these pathologies.