Primary bone lymphoma with cervical compression mimicking solitary osseous plasmacytoma

A 65-year-old woman came to the emergency department complaining of an insidious onset of nocturnal cervical pain and weakness in her extremities.She had no fever, weight loss or night sweats.Physical examination revealed right-sided hemiplegia, bladder dysfunction and constipation.Full blood count, serum calcium, creatinine, albumin, lactate dehydrogenase, beta-2 microglobulin and C-reactive protein showed no abnormal findings.A serum protein electrophoresis with immunofixation and a serum free light-chain assay were normal.Magnetic resonance imaging (MRI) revealed a mass involving the anterior and posterior epidural spaces, compressing the C2-C4 segments with signs of myelopathy (MRI sagittal plane, upper left image).Additionally, a right paravertebral soft tissue component adjacent to the laminae of C3, C4 and C5 demonstrated avid contrast uptake (MRI transverse plane, upper right image).The patient underwent urgent decompression and stabilisation surgery, followed by radiotherapy and glucocorticoids.A vertebral bone biopsy revealed a dense population of large lymphocytes with atypical nuclei, eosinophilic cytoplasm and a conspicuous focal nucleolus (haematoxylin and eosin stain, objective x20, lower left image).Immunohistochemical staining was positive for cluster of differentiation (CD)20, CD10, B-cell lymphoma 6 protein (Bcl-6), paired box transcription factor gene, member 5 (PAX-5) and a antigen Kiel 67 protein (Ki-67) labelling index >80% (CD20 immunohistochemical staining, objective ×20, lower right image).Positron emission tomography-computed tomography did not demonstrate extraosseous disease.The diagnosis was primary bone diffuse large B-cell lymphoma