Symptoms of intervertebral disc herniation as a manifestation of solitary bone plasmacytoma

Abstract

Introduction and Purpose: Solitary bone plasmacytoma (SBP) is a rare, malignant form of plasma cell tumor, commonly diagnosed in people over 50. It usually affects the spine, pelvic bones or long bone structures. Symptoms include pain, restricted movement, muscle weakness, paresthesias. Diagnosis is based on radiological, laboratory and histological examinations. Materials and Methods: A 61-year-old woman presented to a family physician with lumbar spine pain persisting for one year, radiating to her right leg, accompanied by numbness in right foot. Upon detailed examination, a positive right-sided Lasègue test and restricted lumbar motion were noted. Neurological evaluation revealed pain along the right n. ischiadicus projection. A lumbar spine X-ray showed spondylosis. Magnetic resonance imaging (MRI) of the lumbar spine revealed no intervertebral disc herniation but raised suspicion of metastasis. A contrast-enhanced MRI of the lumbar region showed contrast accumulation in the L3 and L4 vertebrae. A CT scan of the spine showed a pathological fracture of the L3 vertebral body caused by an osteolytic neoplasm, with no clear evidence of a neoplasm in L4. Instrumental examinations were performed to search for the primary tumor: DXA showed osteoporosis, X-ray of the pelvis indicated sacroiliitis. No thyroid, gastrointestinal or gynecological primary tumor site was identified. Cancer markers were within normal limits. Suspecting the vertebrae as the primary location of cancer, a vertebral biopsy was taken which revealed SBP. A positron emission tomography/CT was performed, revealing destruction of the L3 vertebra with moderate metabolic activity. Radiotherapy was started and remission was observed. Results: Solitary bone plasmacytoma can be mistaken as an intervertebral disc herniation due to the initial onset of lumbar pain, paresthesia of the lower limbs, and limited lumbar motion. Discussion and Conclusion: Differential diagnosis requires an extensive examination of the patient to exclude other pathologies.