Clinical case study: Multiple myeloma with multiple extramedullary plasmacytomas

摘要

Multiple myeloma (MM) is a neoplastic proliferation of a single clone of plasma cells producing a monoclonal immunoglobulin. Active MM is defined by the presence of an M-protein in the serum or urine, plasma cell infiltration of the bone marrow (at least 10%), and the presence of related tissue or organ impairment. The latter can be remembered by the acronym CRAB: C is elevated calcium, R is renal insufficiency, A is anemia, and B is bone lesions. It is estimated that in 2011 there will be 20,520 new cases of MM and 10,610 deaths. MM accounts for 1% of cancers and 10% of hematologic malignancies.1 The etiology is unknown, though exposure to radiation, benzene, and other organic solvents may be involved. Chronic inflammatory diseases may also play a role, as plasma cell dyscrasias with prolonged stimulation of the reticuloendothelial system have been noted. This disease is highly treatable but rarely curable. It is well known that solid plasmacytomas of the bone and soft tissues can be the initial presentation in patients. Solitary plasmacytoma of the bone (SBP) will often evolve into systemic MM with time; however, plasmacytoma of the soft tissues, oro-pharynx, and other non-osseous presentations less often evolve into systemic MM. Our patient is an extraordinary example of multiple plasmacytomas occurring as the terminal phase of disease.