Pei Lin, MD

Plasmacytoma involving lymph node. The neoplasm has a parafollicular pattern and is composed of mature plasma cells. Note the presence of a lymphoid follicle with a hyperplastic germinal center image.

Plasmacytoma involving lymph node. The neoplasm is strongly CD138(+). A hyperplastic lymphoid follicle that is CD138(−) is at the left of the field image.



  • Extramedullary plasmacytoma (EP)

  • Solitary plasmacytoma of bone (SPB)


  • Extraosseous or osseous plasmacytoma


  • Neoplasm composed of monoclonal plasma cells that involves tissues

    • No evidence of bone marrow involvement

    • No clinical features of plasma cell myeloma

    • Small or absent M-component in urine or serum


Immune Dysfunction

  • T- or B-cell deficiency or autoimmune disorders may play a role in some cases



  • Incidence

    • Rare

      • < 5% of all plasma cell malignancies

    • SPB is more frequent than EP

  • Age

    • Median age ˜ 55 years

      • IgA(+) extramedullary plasmacytomas occur at a younger age

  • Gender

    • Male:female: ˜ 2-3:1


  • Extramedullary plasmacytoma

    • Head and neck is most common site of disease (90%)

      • Upper respiratory tract: Nasopharynx, sinuses, and tonsils

      • ˜ 4% of all nonepithelial tumors of this area

      • Nasal obstruction, epistaxis, mass

      • May spread to cervical lymph nodes in ˜ 15% of cases

    • Gastrointestinal (GI) tract is 2nd most common site

    • Other rare sites of disease

      • Lymph node, bladder, breast, thyroid, testis, brain, skin

  • Solitary plasmacytoma of bone

    • Bone pain, severe back pain, spinal cord compression, pathological fracture

    • Thoracic vertebrae are most common site of disease

    • Lumbar or cervical vertebrae are 2nd most common locations

    • Involvement of distal extremities, below knees or elbow, is rare

Laboratory Tests

  • Small M-component in up to 50% of SPB and in < 25% of EP cases

    • ˜ 20% of EP cases have paraprotein of IgA type

  • Levels of uninvolved Ig are usually normal

  • No anemia or elevated creatinine

  • Serum free light chain ratio may be abnormal


  • Radiation

  • Surgery


  • Prognosis of EP is significantly better than that of SPB

    • ˜ 2/3 are alive for > 10 years

    • Only 15% of EP progress to plasma cell myeloma

  • Survival of SPB is better than that of myeloma patients

    • 50% of SPB patients are alive at 10 years

    • 25-40% are disease free at 10 years

  • 50% of SPB progress to plasma cell myeloma

    • Progression usually occurs within 3-4 years of diagnosis; risk is higher in patients with

      • Large mass (> 5 cm)

      • Persistent M-protein

      • Rising free Ig light chain ratio

  • Recurrences are frequent in SPB and EP


General Features

  • Extramedullary plasmacytoma

    • No evidence of bone involvement

  • Solitary plasmacytoma of bone

    • Single lytic bone lesion

    • No additional lesions by MRI


Histologic Features

  • Diffuse infiltrate of plasma cells

  • EP of head and neck and GI tract more often show mature cytology

  • Plasma cells may show spectrum of maturation from well to poorly differentiated

  • Mature plasma cells

    • Round eccentric nuclei, clumped peripheral nuclear chromatin, and cytoplasmic perinuclear hof

    • Nucleoli absent or inconspicuous

  • Immature plasma cells

    • Pleomorphic nuclei, fine and immature nuclear chromatin

    • Prominent nucleoli

  • Plasmablastic or anaplastic morphology

    • Large nuclei with centrally located nucleoli (immunoblast-like)

Lymph Nodes

  • Plasma cells present in diffuse sheets

  • Partially involved cases have parafollicular or paracortical pattern

    • ± residual lymphoid follicles



Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Plasmacytoma

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