Myeloma

Myeloma

– malignant plasma cell tumor originating from marrow that usu presents with multiple bony lesions
– males > females; presents in 6th decade with pain usu involving vertebrae, ribs or pelvis

Labs:
– anemia, elevated serum Ca, plasmocytosis in bone marrow (>30%)
– serum electrophoresis – globulin spike
– immunoelectrophoresis – high levels of monoclonal immunoglobulins (M components) in serum
– monoclonal light chains in urine (Bence Jones proteinuria)

Xrays:
– multiple or single small, well-circumscribed ‘punched-out’ lytic lesions
– little or no reaction by surrounding bone but endosteal scalloping & medullary expansion
– with long bone involvement, may be cortical destruction with soft tissue mass

Histology:
– tightly packed plasma cells with eccentrically located nucleus, abundant pink cytoplasm & pale-stained juxtanuclear halo
– nodular foci or broad areas of amyloid deposits with no background stroma
– intracytoplasmic inclusions (Russell bodies)

Treatment:
– chemotherapy & radiation (for solitary lesions)
– internal fixation for pathologic or impending pathologic #s