Spine Pain as Initial Presentation of Multiple Myeloma: A Case Report

Case Diagnosis: 77-year-old male presenting with spine pain and proximal muscle weakness diagnosed with multiple myeloma.

Case Description or Program Description: A patient with no significant medical history presented with acute low back pain radiating to left leg after lifting 40-pounds. Conservative treatments at an outside hospital (oral analgesics, physical therapy, epidural injection) failed to provide relief. He noted infrequent healthcare interactions recently. He reported worsening back pain, lower extremity weakness requiring wheelchair for mobility, and weight loss from inactivity/fatigue. On exam he had bilateral proximal muscle weakness and positive lumbar facet loading. XR showed T12 compression fracture. MRI, proximal muscle weakness work-up, and EMG/NCS were ordered.

Setting: Outpatient PM&R Clinic

Assessment/Results: MRI showed moderate bilateral neuroforaminal narrowing and Modic type II endplate changes at L5-Sl; importantly, acute compression fractures at T12, L1 (with 40% height loss), L3. Inflammatory laboratory workup was unrevealing; CBC showed slight pancytopenia. Prior to EMG/NCS completion, patient presented to the emergency department for worsening myalgias and fatigue. Work-up revealed hypercalcemia and worsening pancytopenia. He was diagnosed with multiple myeloma (MM). PET scan revealed myelomatous disease involvement in the left acetabulum and bilateral proximal femurs.

Discussion (relevance): MM presentation is variable; typical features include hypercalcemia, renal dysfunction, anemia, and/or bone pain with lytic lesions. Our patient’s proximal muscle weakness was likely due to hypercalcemia, myelomatous disease involvement, or paraneoplastic syndrome. Vertebral fracture from osteolytic lesions contributed to pain. Our patient’s weight loss, myalgias, minimal trauma vertebral fracture, and proximal muscle weakness were clues to consider an alternative systemic diagnosis.

Conclusions: This is an unusual presentation of MM. A thorough history and physical are critical to identifying clues or exam findings inconsistent with typical back pain pathologies. It is important to consider a wide differential even when patient-reported symptoms align with classic radicular or other back-pain symptoms as systemic processes such as cancer can present with similar pain.