Extraosseous Spread of Multiple Myeloma Mimicking Pancoast Tumor

A 55-year-old man presented with upper backache for one month, inability to move both the lower limbs for two weeks and retention of urine for five days. Examination revealed spastic paraplegia and reduced breath sounds in the right upper zone. Initial imaging revealed a soft tissue lesion in the apex of the right lung, suggesting a Pancoast tumor. It also showed a lytic, expansile lesion of the T2 vertebra extending to the right second posterior rib on subsequent imaging. High serum calcium, M-spike in beta-gamma globulin region on serum electrophoresis, 50%-60% plasmacytoid cells on bone marrow aspiration, concertina collapse of the vertebral body, and pattern of neurological deficit pointed towards multiple myeloma. T2 corpectomy and mesh cage placement, C7-T4 posterior stabilization, and resection of the second rib were done. Histopathology confirmed multiple myeloma. Postoperatively, the patient was managed with radiotherapy and bortezomib. The patient had a good neurological recovery. Timely intervention is critical for disease control and leads to better recovery.