Neoplastic degeneration of plasma cells can show different clinical features, including multiple myeloma and plasma cell leukemia. Skin involvement is not rare in patients with multiple myeloma, and represents a poor prognosis. Appearance of a cutaneous plasmacytoma without the involvement of bone marrow is very rare. We describe a patient who had cutaneous plasmacytoma, with two solitary lesions of the oral cavity. The patient also showed a cerebral involvement, but no evidence of multiple myeloma, with normal-appearing bone marrow.