Solitary Plasmacytoma of Mandible Transforming to Multiple Myeloma? - A Rare Case Report

Background: Plasma cell dyscrasias is proliferation of the plasma cells that typically produces monoclonal immunoglobulin. Solitary plasmacytoma, multiple myeloma, and extramedullary plasmacytoma are their three distinct clinical entities. The most common among the plasmacytoma is the solitary bone type which accounts for less than 450 cases annually and constitutes only 2% to 5% of all plasma cell malignancies In case of solitary plasmacytoma, it is significant to make dissimilitude of whether minimal bone marrow clonal plasmacytosis are there or not, solitary bone lesion or soft tissue, negative whole-body imaging for further lesions, anemia and renal dysfunction. Almost 50% Solitary plasmacytoma cases shows transformation into multiple myeloma. Case Presentation: A 58 years old female patient with single, diffuse tumour mass in the left mandibular region of oral cavity was subjected for clinical, radiological, histopathological, immunohistochemical and biochemical investigation. The diagnosis of solitary plasmacytoma was done. But with correlation of all the investigation a suspect of transformation into multiple myeloma arise. Discussion: Despite of the excellent local control rates, majority of solitary plasmacytoma will eventually progress to multiple myeloma. Previous studies on solitary plasmacytoma had shown 5-year overall survival rate as 70% and 5-year of disease-free survival rate as 46%, with median time for development of multiple myeloma as 21 months, with a 5-year probability of 51%. Conclusion: Solitary plasmacytoma being a rare plasma cell malignancy with high potency to transform into multiple myeloma, a thorough investigation is needed before diagnosis. Early diagnosis and appropriate treatment is the key to increase disease free survivial rate of the patient.