Background: Plasmacytoma is a localized clonal proliferation of plasma cells that occur in the absence of bone marrow and systemic involvement. Extra medullary plasmacytoma most commonly involves the aerodigestive tract in 80% of cases, mainly in the head and neck with lymph nodes involvement. It usually results from the metastasis of the primary extra-medullary plasmacytoma or as part of a systemic MM involvement or plasma cell leukemia. Moreover, primary lymph node extra-medullary plasmacytoma is exceedingly rare, and it constitutes around 2% of EMP. Most cases are of solitary lymph node involvement. Nevertheless, PLNEMP with widespread lymph nodes involvement is rarer, with less than 10 reported cases worldwide. The localized nature of plasmacytoma is generally treated with localized measure i.e.: Radiotherapy and less commonly surgical excision, however, in cases of diffuse involvement such as our case -when the radiotherapy is not feasible- there is no consensus treatment guideline. Here, we present a case of wide spread PLNEMP that is treated with myeloma specific regimen followed by autologous stem cell.
Case Report: A case of a 51-year-old man presented with progressive shortness of breath in the setting of a thickwalled cystic subcutaneous lesion, noted in the suprasternal area and several mildly enlarged left lower cervical, mediastinal and right hilar lymph nodes. Diagnosis of lymphoma was initially suspected; however, a lymph node biopsy was consistent with plasmacytoma. Also, a bone marrow biopsy was unremarkable, and a monoclonal band was present in the Gamma area, measuring approximately 0.4 gm/dL. It is found to be IgG Lambda by Immunofixation. Moreover, there was no evidence of end organ damage; thus establishing a diagnosis of primary extra-medullary plasmacytoma of the lymph nodes. The patient was treated with a myeloma-adapted regimen consisting of 3 cycles of VTD that result in VGPR ,however due to thalidomide related SNHL the cyclophosphamide substitutes thalidomide and 3 more cycles of VCD regimen given and was referred to autologous stem cell transplant as consolidation.
Conclusion: The importance of this extra-medullary plasmacytoma case came from its rare presentation, location and type of treatment received. There was only one previous case with this presentation treated with novel myeloma therapy and it is the only case that received ASCT as consolidation treatment according to literature review included in this case report.