Large mass centered on the right lamina of C7, causing moderate spinal cord compression (but no cord signal change) and compression of severe right-sided nerve roots. The presence of at least two further masses makes lymphoma, myeloma or metastases the likely diagnoses.
The diagnosis was subsequently proven histologically from a biopsy of the femur which had an additional deposit.
MICROSCOPIC DESCRIPTION: Sections of the bone show a proliferation of atypical lymphoid cells in the medullary spaces. They form loose aggregates and sheets. No follicular structures are seen. The atypical cells are large in size. They have enlarged clefted and hyperchromatic nuclei, prominent nucleoli and scanty cytoplasm. The background contains small mature lymphocytes. The atypical lymphoid cells are CD20, PAX-5, bcl-2, bcl-6 and MUM1 positive. There is also focal staining for CD23. The Ki-67 index is about 35%. CD3, CD5, CD10 and Cyclin D1 are negative.
The features are those of diffuse large B-cell lymphoma, not otherwise specified, with activated B-cell-like phenotype.
FINAL DIAGNOSIS: Diffuse large B-cell lymphoma.