When an unusual lesion occurs in an odd place

Solitary plasmacytoma is a localized osseous tumor of asingle focus of plasma cells [1,2]. The tumor may manifestclinical features different from those of the more commondisseminated form, multiple myeloma [3–6]. Solitary plas-macytomas comprise less than 3% of all primary spinal neo-plasms [1,2,3,4,7]. It is uncommon for plasmacytoma to occurhigh in the cervical spine [4,5] and is seldom reported as a causeof atlantoaxial dislocation. Differentiation of plasmacytomafrom tuberculosis of the spine is sometimes difficult.

A 40-year-old male experienced insidious onset with pro-gressively severe occipitocervical pain and restriction ofneck movement over 8 months. For 5 months he had sufferedprogressive, spastic quadriparesis and numbness, and for 2months he had been bedridden. He had had a low grade feverand had been, until referral to our institute, treated with antitu-bercular chemotherapy. Our examination documented weak-ness in the range of 0–4/5 in all extremities, most profound inthe lower extremities, and sensory dysfunction below C4.

Lateral radiograph of the cervical spine shows a loss ofnormal lordosis increased prevertebral soft tissue shadow,decreased C2–C3 disc space, and destruction of the vertebralbody and odontoid process of C2 (Fig. 1A). Computed to-mography demonstrated an expansile destructive lesion ofthe body and odontoid process of C2, atlantoaxial dislocation,

Fig. 1. Lateral radiograph of the cervical spine shows loss of normallordosis, increased prevertebral soft tissue shadow, decreased C2–C3 discspace, and destruction of the vertebral body and odontoid process of C2(A). Computed tomography demonstrated an expansile destructive lesionof the body and odontoid process of C2, atlantoaxial dislocation, and C2–C3 subluxation (not shown).

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Magnetic resonance imaging (MRI) in T-2 weighted, sagittal image (B)shows a well-defined expansile destructive mass involving the odontoidprocess, vertebral body, and left half of the lamina and spinous process ofC2. Hyperintense signal changes can be seen within the cord at the focalarea of stenosis at the C2 level.

and C2–C3 subluxation (not shown). Magnetic resonance im-aging (MRI) in T-2 weighted, sagittal image (Fig. 1B),shows a well-defined expansile destructive mass involvingthe odontoid process, vertebral body, and left half of the laminaand spinous process of C2. Hyperintense signal changes canbe seen within the cord at the focal area of stenosis at theC2 level.

Since our patient had myelopathy and MRI showing intra-medullary spinal cord changes, we proceeded, on an urgentbasis, with transoral excisional biopsy (Fig. 2A) and decom-pression followed by posterior decompression and stabiliza-tion (Fig. 2B), done under the same anesthetic. We found thebody and odontoid of C2 to be completely destroyed bygrayish-red, vascular tissue.

Histologic preparation of biopsy from the transoral expo-sure (Fig. 2A) shows sheets of malignant plasma cells.Immunochemistry proved the cells positive for CD-138, epi-thelial membrane antigen (EMA), vimentin and lambda light

Fig. 2. Histologic preparation of biopsy from the transoral exposure. (A)Sheets of malignant plasma cells. Immunochemistry proved the cells posi-tive for CD-138, epithelial membrane antigen (EMA), vimentin and lambdalight chain—all confirming the diagnosis of myeloma or plasmacytoma. Thecord was further decompressed by laminectomy and the spine stabilizedby stainless steel contoured loop with sublaminar wiring and iliac graft (B).

chain—all confirming the diagnosis of myeloma or plas-macytoma. The cord was further decompressed by laminec-tomy and the spine stabilized by stainless steel contouredloop with sublaminar wiring and iliac graft (Fig. 2B).

Plasmacytoma and multiple myeloma are considered twomanifestations in a continuum of beta-cell lymphoproliferativediseases. A distinction between plasmacytoma and multiplemyeloma is that the latter is associated with plasmacytosis ofbone marrow and the presence of IgG-lambda monoclonalimmunoglobulin in both the serum and the cytoplasm of thetumor cells [8]. Solitary plasmacytoma may progress to adisseminated form, and frequently does so within 15 years[8]. Even with progression, the prognosis is more favorablefor those with an initial diagnosis of plasmacytoma.

The diagnosis of solitary plasmacytoma requires: histologicevidence of the lesion; absence of other lesions by imaging as-sessments; negative bone marrow examination; and absenceof dysproteinemia and Bence Jones proteinuria. A review of84 cases of solitary plasmacytoma showed that 61% occurred

in the thoracic spine, 18% in the lumbar spine, and only 8% inthe cervical spine [2]. They reported that, while 60% remaineddisease-free for 5 years, 44% developed disseminated diseasebetween 2 and 13 years after the diagnosis of plasmacytoma.

Only 4 cases of solitary plasmacytoma and 5 cases ofmultiple myeloma at the craniovertebral junction have beenreported [6,7,9,10,11]. In the two largest series of craniover-tebral junction abnormalities there were no cases of myelomaat C2 [12–14]. There are a few case reports of multiplemyeloma of the axis and atlas and of solitary plasmacytomaof C2 [7,9,10,11]. In India, tuberculosis is a common causeof atlantoaxial instability. MRI features that distinguish plas-macytoma from tuberculous spondylitis are not describedadequately [15].

Our patient is the first case in the literature of solitaryplasmacytoma of the axis managed by transoral decompres-sion and posterior occipital-cervical fixation. Postoperatively,he received 4000 rads of radiotherapy over 6 weeks, and chemo-therapy. Two years later hewas able to walk and care for himselfand had no evidence of local recurrence or multiple myeloma.

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[9] Hasting DE, Macnab I, Lawson V. Neoplasms of the atlas andaxis. Canadian J Surg 1968;11:290–6.

[10] Taro Kaibara R, Hurlbert J, Sutherland GR. Transoral resection ofaxial lesions augmented by intraoperative magnetic resonance im-aging: report of three cases. J Neurosurg 2001;95:239–42.

[11] Viewag U, Meyer B, Schremm J. Tumor surgery of the upper cervicalspine. Acta Neurochir (Wien) 2001;43:212–25.

[12] Crockard H. Transoral surgery, some lessons learned. Br J Neuro-surg 1995;9:283–93.

[13] Menezes AH. Craniovertebral junction anomalies, diagnosis andmanagement. Seminar Paediatr Neurol 1997;4:209–23.

[14] VanGidler JC, Menezes AH. Craniovertebral anomalies and their treat-ment. In: Schmideck HH, Sweet WH, editors. Operative neurosurgicaltechniques, indications, methods, and results. New York, NY: WBSaunders, 1995:1221–35.

[15] Gupta RK. Problems in distinguishing spinal tuberculosis fromneoplasm on MRI. Neuroradiology 1996;38:S97–S104.

DeepakKumarGupta,MCh,AshishSuri,MBBS,MCh,DNB,Ashok Kumar Mahapatra, MCh, Veer Singh Mehta, MCh,Chitra Sarkar, MD, Lalit Kumar, MD, New Delhi, India

doi:10.1016/j.spinee.2005.01.003