PMC5437794_01
(a) Magnetic resonance imaging showing lytic lesion involving L5 with epidural soft tissue. (b) Postradiotherapy changes after completion of curative radiotherapy. (c) Recurrence in L5 with large epidural soft-tissue component. (d) Residual lesion after decompressive laminectomy and excision. (e and f) Magnetic resonance imaging and computer tomography scan showing complete resolution of lesion after nine courses of bortezomib, lenalidomide, and dexamethasone regimen
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F1
Hence, magnetic resonance imaging (MRI) of the lumbosacral spine (LS) was done which showed lytic lesion in L5 vertebral body and left pedicle, transverse process, and superior articular facet Figure 1a. MRI after RT was suggestive of post-RT changes and hence the patient was kept on observation [Figure 1b]. Repeat MRI of the LS and pelvis with whole spine screening was suggestive of recurrent lesion with large paraspinal soft-tissue component at L5 vertebral level [Figure 1c]. Postlaminectomy MRI revealed residual paraspinal lesion extending to L4-L5 level compressing the exiting nerve roots [Figure 1d]. Repeat MRI after four courses showed significant regression of paraspinal mass with complete neurological recovery [Figure 1e]. After completion of nine courses, contrast-enhanced CT scan of the LS spine was performed which showed complete resolution of paraspinal mass and no evidence of any abnormal lytic lesion at the operated site [Figure 1f].
(a) Computed tomography biopsy showing malignant round cell tumor morphologically large cell lymphoma (b) leukocyte common antigen positive (c) CD 79a positive (d) multiple myeloma oncogene-1 positive (e) CD 20 negative (f) AE 1 negative (g) CD 99 negative
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F2
Computerized tomography (CT)-guided biopsy from the vertebral lesion was suggestive of malignant round cell tumor, morphologically large cell lymphoma [Figure 2a]. Immunohistochemistry (IHC) study revealed leukocyte common antigen, CD79a and multiple myeloma oncogene-1 (MUM1) positive with CD 20, AE 1, and CD 99 negative and MIBI of 20% [Figure 2b-g].
(a) Laminectomy specimen showing mature binucleate plasma cells (plasmablasts) (b) epithelial membrane antigen positive (c) CD 138 positive (d) multiple myeloma oncogene-1 positive suggestive of plasmacytoma
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F3
Histopathological examination of laminectomy specimen showed proliferation of mature binucleated plasma cells (plasmablasts) [Figure 3a]. Further IHC confirmed MUM1 strong positive, epithelial membrane antigen, and CD 138 positive in mature plasma cells [Figure 3b-d] with CD 20, CD 99, and CD 1a negative.