Hematologic neoplasms
Solitary plasmacytoma

Topic Completed: 1 April 2014

Revised: 10 July 2019

Copyright: 2003-2019,, Inc.

PubMed search: solitary plasmacytoma [title] bone

Sheren Younes, M.D.
Page views in 2018: 1,942
Page views in 2019 to date: 1,462
Cite this page: Younes S. Solitary plasmacytoma. website. Accessed October 20th, 2019.
Definition / general
  • Defined by WHO 2008 as a localized bone tumor consisting of monoclonal plasma cells, with no other bone lesions, no bone marrow involvement and no clinical features of myelomas
  • Rare; < 5% of myeloma patients
  • Majority are males
  • Median age is 50 - 55 years
  • Sites of active bone marrow hematopoiesis
  • 40 - 60% in axial spine; also vertebrae, thoracic more than lumbar and cervical
  • Followed by ribs, skull, pelvis, femur, clavicle, scapula
  • Long bone involvement below elbow and knee are rare
  • Rarely involves lymph nodes or peripheral blood
Clinical features
  • Incidental finding
  • May have bone pain and pathologic fracture
  • May cause soft tissue mass
  • Diagnostic criteria:
  • Single bony lesion consisting of monoclonal plasma cells; MRI may be needed to exclude involvement of other sites
  • No bone marrow involvement
  • No clinical features of myeloma, such as anemia, hypercalcemia and renal failure
  • Absence or low levels of M protein in urine
  • Normal levels of uninvolved polyclonal immunoglobulins (Br J Haematol 2004;124:717)
  • CBC, renal function tests, serum calcium (to exclude myeloma)
  • Immunofixation studies in serum and urine (M protein detection)
Radiology description
  • Osteolytic lesions, similar to myeloma
  • May show soft tissue extension
  • Vertebral involvement may be associated with spinal cord or nerve root compression
Radiology images

Contributed by Dr. Mark R. Wick

Pelvis Xray

Skull Xray

Images hosted on other servers:

Lobulated osteolytic sternal lesion

Prognostic factors
  • Median survival is 10 years
  • 50% eventually develop myeloma, 1/3 remain disease free > 10 years after radiotherapy
  • Poor prognostic factors are large size and M protein persistence after radiotherapy
Case reports
  • Local control by radiotherapy is curative for most cases
Clinical images

Images hosted on other servers:

Huge, firm, nonpulsatile anterior chest wall mass

Microscopic (histologic) description
  • Similar to myeloma, easily diagnosed unless plasmablastic or anaplastic
  • Cytologic, immunophenotypic and molecular features are similar to myeloma
Microscopic (histologic) images

Contributed by Dr. Mark R. Wick

With amyloid and Congo red stain

Images hosted on other servers:

Various images

H&E, CD45+, CD10+

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