Unicentric Plasma Cell Variant Castleman Disease

Unicentric Plasma Cell Variant Castleman Disease

Pei Lin, MD

Lymph node involved by unicentric Castleman disease, plasma cell variant (CD-PV). Multiple follicles are present and the interfollicular zones are expanded by plasma cells.

Lymph node involved by unicentric CD-PV. This field shows interfollicular plasma cells and a follicle with a small germinal center with involution (regressive changes) image.



  • Castleman disease, plasma cell variant (CD-PV)


  • Unicentric Castleman disease, plasma cell variant

  • Angiofollicular lymph node hyperplasia

  • Giant lymph node hyperplasia

  • Angiomatous lymphoid hamartoma

  • Benign giant lymphoma


  • Histologically distinctive reaction pattern in lymph node characterized by

    • Marked interfollicular plasmacytosis

    • Regressive (hyaline-vascular) changes in small subset of follicles in subset of cases



  • Data supporting role for dysregulation of interleukin-6 (IL-6) in pathogenesis

    • Lymphocytes in CD-PV express IL-6

    • B cells express IL-6 receptor (CD126)

      • Autocrine or paracrine mechanisms may be involved

    • In mice, forced expression of IL-6 in bone marrow cells causes syndrome that resembles, in part, CD-PV

  • Immune dysregulation also may be involved

  • As defined in this chapter, there is no evidence of human herpes virus 8 (HHV8) infection



  • Incidence

    • Accounts for 10-20% of localized or unicentric cases of CD

  • Age

    • Broad range; median in 3rd-4th decade

  • Gender

    • No preference


  • Peripheral lymph nodes most common

  • Mediastinal involvement less common (than hyaline vascular variant of CD)


  • Most patients present with lymphadenopathy without systemic symptoms

  • 10-20% of patients reported in literature had systemic symptoms

    • Fever, night sweats, weight loss, malaise

    • However, it seems likely that many of these patients were HHV8(+)

      • Therefore better classified as HHV8-associated &/or multicentric CD

  • Small subset of patients reported were associated with POEMS syndrome

    • POEMS = peripheral neuropathy, organomegaly, endocrinopathy, monoclonal M protein, skin lesions

    • These patients also likely to be HHV8(+)

      • Probably better classified as HHV8-associated &/or multicentric CD

Laboratory Tests

  • Many patients lack laboratory abnormalities

  • Subset of patients (˜ 10-20%) can have cytopenias

    • Anemia and thrombocytopenia

  • Serum IL-6 levels can be increased


  • Surgical approaches

    • Usually curative by excision


  • Good

  • Small subset of patients may evolve to multicentric CD

    • Possibly were cases of multicentric CD at time of initial biopsy


Radiographic Findings

  • Lymphadenopathy

    • Often multiple lymph nodes in an anatomic group are large

  • PET scan shows increased FDG uptake



  • Usually lymphadenopathy is of modest size


Histologic Features

  • Less well defined than HV-CD

  • Preserved overall lymph node architecture

  • Marked plasmacytosis in interfollicular areas

    • Some plasma cells can be binucleated

  • Vascularity in interfollicular areas can be prominent

  • Sinuses usually patent

  • Widely spaced lymphoid follicles

  • Lymphoid follicles contain hyperplastic germinal centers, but small subset of germinal centers often show regressive changes

    • Resemble follicles seen in CD-HV

    • Others have used term “mixed or transitional” type because of these follicles

    • Atretic follicles are usually present and part of spectrum of CD-PV

  • Mantle zones are usually well defined and can be expanded

    • Plasmablasts are absent or rare in mantle zones

Cytologic Features

  • Plasma cells are cytologically normal without atypia

  • Lymphocytes show range in cytologic appearance

  • Difficult to establish specific diagnosis of CD-PV by fine needle aspiration



  • Interfollicular plasma cells express polytypic immunoglobulin light chains

  • Follicles composed of polytypic B cells and T cells

    • Germinal centers are Bcl-2(-)

    • Atretic follicles show increased follicular dendritic cells

      • CD21(+), CD23(+), CD35(+)

  • Rare cases are reported with monoclonal plasma cells

    • These cases most likely HHV8(+) &/or multicentric CD

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Unicentric Plasma Cell Variant Castleman Disease

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