Abstract:

INTRODUCTION Plasma cell dyscrasias include a wide variety of diseases characterized by the abnormal accumulation of plasma cells resulting in various systemic symptoms and signs. Plasma cells are usually widespread throughout the bone marrow; however, in a minority of patients malignant plasma cells may form a single lesion. These lesions are usually confined to the bone and, less frequently, in extramedullary sites. They are composed of monoclonal plasma cells that are otherwise identical to plasma cells found in myeloma. However, these patients do not have evidence of systemic multiple myeloma (MM), and an extensive work up shows no other foci of disease. When this solitary lesion is confined to bone it is characterized as a solitary bone plasmacytoma (SBP) while when this lesion is confined to extraosseous sites it is characterized as a solitary extramedullary plasmacytoma (SEP). DEFINITIONS According to criteria reported by the International Myeloma Working Group, diagnosis of solitary plasmacytoma of bone is based on histological evidence of a tumor consisting of monoclonal plasma cells identical to those seen in MM (Table 12.1). In addition, complete skeletal radiographs must show no other lesions of MM. Magnetic resonance imaging (MRI) has significantly increased sensitivity over conventional radiographs, especially in the imaging of the axial skeleton, and an MRI of the spine and pelvis may show unsuspected and asymptomatic skeletal lesions. Patients with multiple lesions in MRI should be considered as having myeloma and not SBP even if conventional radiographs show no other evidence of skeletal involvement. © Cambridge University Press 2009.

Notes:

Export Date: 21 February 2017

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