Extramedullary Multiple Myeloma: A Rare and Aggressive Variant

Extramedullary multiple myeloma (EMM) is an aggressive variant of Multiple Myeloma characterized by proliferation of malignant plasma cells outside the bone marrow. It is associated with advanced disease, resistance to therapy, and poorer prognosis. We report a 63-year-old male who presented with fever, productive cough, progressive exertional dyspnoea, significant weight loss, and generalized weakness over two months. Laboratory investigations revealed severe pancytopenia, hypercalcaemia, acute kidney injury, and marked hypergammaglobulinemia with rouleaux formation on peripheral smear. Serum protein electrophoresis demonstrated a monoclonal spike, and immunotyping confirmed IgG lambda monoclonal gammopathy. Bone marrow examination showed approximately 40% abnormal plasma cells consistent with multiple myeloma. Imaging studies revealed diffuse lytic skeletal lesions and splenomegaly with multiple focal splenic lesions suggestive of extramedullary involvement. Based on clinical, laboratory, and radiological findings, a diagnosis of IgG lambda multiple myeloma with probable extramedullary disease was established. This case highlights the importance of early recognition of extramedullary manifestations, which significantly influence disease prognosis and therapeutic strategy.