Multiple myeloma other diagnostic studies

Bone Marrow Biopsy
A bone marrow biopsy is usually performed to estimate the percentage of bone marrow occupied by plasma cells. This percentage is used in the diagnostic criteria for myeloma.

Diagnostic criteria
In 2003, the International Myeloma Working Group agreed on diagnostic criteria for symptomatic myeloma, asymptomatic myeloma and MGUS (monoclonal gammopathy of undetermined significance):


 * Symptomatic myeloma:
 * Clonal plasma cells >10% on bone marrow biopsy or (in any quantity) in a biopsy from other tissues (plasmacytoma)
 * A monoclonal protein (paraprotein) in either serum or urine
 * Evidence of end-organ damage (related organ or tissue impairment, ROTI):
 * Hypercalcemia (corrected calcium >2.75 mmol/L)
 * Renal insufficiency attributable to myeloma
 * Anemia (hemoglobin <10 g/dL)
 * Bone lesions (lytic lesions or osteoporosis with compression fractures)
 * Frequent severe infections (>2 a year)
 * Amyloidosis of other organs
 * Hyperviscosity syndrome
 * Asymptomatic myeloma:
 * Serum paraprotein >30 g/L AND/OR
 * Clonal plasma cells >10% on bone marrow biopsy AND
 * NO myeloma-related organ or tissue impairment
 * Monoclonal gammopathy of undetermined significance (MGUS):
 * Serum paraprotein <30 g/L AND/OR
 * Clonal plasma cells <10% on bone marrow biopsy AND
 * NO myeloma-related organ or tissue impairment

Related conditions include solitary plasmacytoma (a single tumor of plasma cells, typically treated with irradiation), plasma cell dyscrasia (where only the antibodies produce symptoms, e.g. AL amyloidosis), and POEMS syndrome (peripheral neuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes).