liveonearth (liveonearth) wrote,

Plasma Cell Dyscrasias: Multiple Myeloma & Waldenstrom's Macroglobulinemia

A group of clinically and biochemically diverse diseases characterized by proliferation of ONE clone of plasma cells normally engaged in immunoglobulin production. PCD's account for 15% of WBC neoplasms. Typified by the presence of a monoclonal Ig or polypeptide subunit (fragment) in serum or urine. Monoclonal immunoglobin in the blood is referred to as "M component".

All are composed of terminally differentiated B cells, arise in the bone marrow, secrete whole Ab's or immunoglobulin fragments, cause bony destruction. Patients present with pain dt pathologic fractures.

Five types including related disorders:
1) Multiple Myeloma
2) Waldenstrom's macroglobulinemia
3) Heavy Chain dz
4) Primary or immunocyte-associated amyloidosis
5) MGUS = Monoclonal gammopathy of undetermined significance. MGUS is common in elderly pts and has no signs or symptoms.

--3-5% of plasma cell neoplasms are solitary lesion in bone or soft tissue
--bony lesions occur in axial skeleton like multiple myeloma
--soft tissue lesions in: lung/ oronasopharynx, nasal sinuses
--progression to multiply myeloma common w/ bony lesions, 10-20 years

--most important and common monoclonal gammopathy
--causes about 1% of all cancer deaths in the west
--more in males, Africans, elderly
--peak age 50-60 yo.
--progressive neoplastic dz of plasma cells in multifocal spongy bone marrow sites
--pelvis, spine (most common), ribs, skull
--can spread to lymph nodes and extranodal sites, ie: skin
--increased production of specific monoclonal immunoglobulin (Ig: G, A, D, E)
--IgG 55%, IgA 20%, "M protein"
--urinary BENCE JONES protein (free monoclonal kappa or delta light chains) sulfosalicylic acid test to detect, causes "myeloma kidney"
--Dx: 99% of pts have elevated Ig's in blood and/or light chains in urine
--light chain => higher bone lytic lesions and assoc hypercalcemia (1/3) and renal failure
--S/Sx: recurrent bacterial infx dt decreased production of other Ig's ???, unexplained back pain (thorax too), renal failure, pathological bone pain
--CNS S/Sx: confusion, weakness, lethargy, constipation, polyuria
--mb pathological fx in vertebrae, sudden collapse makes pt shrink inches overnight
--mb anemia; normocytic, normochromic
--ESR > 100 mm/hr: RBCs form rouleaux dt increased viscousity dt abn prots
--WBC & PLT usu normal
--total prot, BUN, creatinine, uric acid: all elevated
--pts die of 1) infx 2) renal dz
--pathogenesis: IL-6 promotes prolif & survival of myeloma cells, factors produced by these cells destroy bone (MIPIalpha and NFkappaB ligand are osteoclast-activators)
--x-ray: bones show "moth eaten look" aka punch-out lesions, 1-4 cm in size
--less common: diffuse demineralization (osteopenia)
--Dx: definitive: marrow biopsy, 30%+ plasma calls w/ multiple & prominent nucleoli
--rare: plasma cells flood PB --> plasma cell leukemia

--3% of all NHL in US, 7-9% in Europe
--age 50-60, more in males
--tumors resemble the normal mantle zone B cells
--morph: homogenous small lymphs with irreg nuclei, condensed chromatin, scant cytoplasm
--S/Sx: generalized LAD
--extranodal involvement: marrow, splenic white pulp, hepatic periportal, small bowel/colon "lymphomatoid polyposis"
--PROGnosis: poor, 3-4 year survival rate
--Not curable via chemo/radiation

--clonal expansion of plasma cells that make IgM, clogs plasma-->Raynaud's
--resembles lymphoma and many clinical manifestations dt large amounts of circulating macroglobulin
--recurrent bact infx are major problem
--S/Sx: most are ASX, may have indications of hypervicousity syndrome (fatigue, bleeding, weakness, visual disturbances, headaches, Raynaud's)
--moderate anemia
--very high ESR (marked rouleaux formation)
--leukopenia, relative lymphocytosis and thrombocytopenia occasional
--cryoglobulins, rheumatoid factor, cold agglutinins mb present
--relative serum viscousity usu over 4.0 (normal 1.4-1.8)
Tags: blood, cancer, diagnosis, immunology, nd2, protein

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