Plasmacytoid lymphomas

• Multiple myeloma

  • Most common plasma cell dyscrasia

  • Peak at 50-60 YOA, both sexes equally affected

  • Monoclonal IgG most frequently seen (55%), followed by IgA (25%) or light chain only (25%); serum concentrations of these are generally > 3 g/dL

  • Poor prognosis if Bence-Jones protein levels > 6 mg/dL from renal damage and generalized amyloidosis

  • May have “punched out bone lesions” or generalized osteoporosis; both lead to pathological fractures

  • Hypercalcemia from bone resorption may lead to confusion, weakness, lethargy, C, and PU

  • Believed to be a disease of hematopoietic stem cells

  • Suppression of normal Ig production can lead to recurrent infection with encapsulated bacteria

  • 7% of patients have hyperviscosity (especially with monoclonal IgA since it forms polymers); see retinal hemorrhages, prolonged bleeding, and neurologic changes like H/A, dizziness, deafness, and stupor

  • Peripheral blood findings: normochromic and normocytic anemia, rouleaux formation, and rarely leukemic involvement (plasma cell leukemia)

  • Increased plasma cells in marrow in a diffuse or nodular pattern (must be discriminated from causes of reactive plasmacytosis)

  • Solitary plasmacytoma

    • Infrequent variant with an isolated mass of neoplastic cells in bone or soft tissue

    • Soft tissue plasmacytoma often cured with just surgery; osseous plasmacytoma progresses to multiple myeloma no matter what the therapy (may take up to 20 years to do so, though)

  • Called light-chain or heavy-chain disease in the absence of demonstrable associated heavy chains or light chains, respectively

  • Chromosome 14 problems have been seen (worse prognosis)

  • Prognosis depends on stage at time of diagnosis

    • Those with multiple bone lesions rarely live more than a year if untreated

    • May increase survival to 2-3 years with advanced cases using chemo with alkylating agents

    • Elevated IL-6 levels associated with poor prognosis (IL-6 causes proliferation and differentiation of myeloma cells)

• Waldenstrom’s macroglobulinemia

  • Disease of old age (60 and 70 YOA)

  • Monoclonal IgM with diffuse infiltrate of “plasmacytoid lymphocytes” in the marrow, nodes, liver, and spleen

  • Lytic bony lesions are absent

  • Often seen with hyperviscosity because of larger size of IgM

  • May get things like Raynaud’s phenomenon or cold urticaria if abnormal Igs precipitate with cold temperatures

  • Average survival with appropriate chemo = 2-5 years

• Heavy chain disease

  • κ chain disease

    • Most common type

    • Mostly in young adults, especially in the Mediterranean area

    • Massive infiltration of lamina propria of the intestine and abdominal nodes resulting in villous atrophy and severe malabsorption with D, steatorrhea, and hypocalcemia

    • Progressive and uniformly fatal

    • May occur as a complication of sprue

  • κλchain disease

    • In elderly where it resembles a malignant lymphoma with lymphadeopathy, anemia, and F, often also with malaise, weakness, and hepatomegaly or splenomegaly

    • Course is variable

  • λ chain disease

    • Rarest type

    • Often in patients with CLL

    • Hepatosplenomegaly is usually present, but peripheral lymphadeopathy is inconspicuous

• Monoclonal gammopathy of uncertain significance

  • See monoclonal serum Ig without demonstrable evidence of defined plasma cell dyscrasia or lymphoproliferative syndrome

  • Seen in 1% of asymptomatic healthy folk over 50 YOA and in 3% of people > 65 YOA

  • Monoclonal serum protein usually of IgG with serum concentration <>

  • Bence Jones proteinuria is usually absent

  • About 20% of these eventually develop a plasma cell dyscrasia, malignant lymphoma, or amyloidosis

  • Normal Igs don’t decrease in number

Category: Medical Subject Notes , Pathology Notes