Plasma Cell Leukaemia: Rare Presentation Of Relapse Multiple Myeloma: A Case Report And Literature Review

Abstract

Background: Plasma cell leukaemia (PCL) is a very rare and aggressive clinical variant of plasma cell dyscrasias with a dismal prognosis. Not less than 28% of patients die within one month after diagnosis. It could arise de novo and is known as primary plasma cell leukaemia (pPCL) or following a diagnosis of MM and is known as secondary PCL (sPCL) occurring mostly during the post chemotherapy period or relapse/refractory MM. Secondary PCL has a relative incidence estimated at 30–40%, and is said to occur in 1.8-4% of all cases of MM. Diagnosis is based on the presence of circulating plasma cell in excess of 20% or an absolute count of greater than 2 x109/L. The clinical presentation of PCL differs from that of MM. Case Presentation: A 48 year old lady previously diagnosed with multiple myeloma and managed with CyBorD three years prior to the index presentation. She presented with unprovoked fracture of the arm and full blood count revealed a differential plasma cell count of 35% with an absolute count of 4.1 x 109/L. She was diagnosed as a case of sPCL and managed with CyBorD-AR. Patient however succumbed to the disease within two months of presentation due to the aggressive nature of her condition. Conclusion: Our case report highlights the clinical heterogeneity of dyscrasias where MM relapsed with PCL which is a rare and aggressive clinical variant of the dyscrasias with dismal prognostic outcome.