Surgical Resection of Solitary Bone Plasmacytoma of Atlas and Reconstruction with 3-Dimensional-Printed Titanium Patient-Specific Implant.

Background: Solitary plasmacytoma of bone (SPB) is a rare malignancy of localized osseous lesion consisting of neoplastic monoclonal plasma cells. Recommended treatment of SPB includes a combination of surgery and radiation therapy. We present a rare case of SPB lesion in the atlas requiring surgical resection, followed by restoration of atlas stability with a custom 3-dimensional-printed (3DP) patient-specific implant (PSI).

Case Description: A 57-year-old man presented with severe neck pain. Assessment by radiographs, computed tomography, and magnetic resonance imaging was found to harbor a single osteolytic lesion at the C1 (atlas) vertebra. Diagnostic tumor screening returned negative results. Transoral biopsy suggested solitary plasmacytoma. Spinal instability was apparent-hence the decision for surgical intervention via the retropharyngeal external approach to resect the lesion. Atlas reconstruction and stabilization were achieved using a custom 3DP titanium PSI. Subsequent pathologic findings confirmed plasma cell infiltration of the atlas. Histologic evaluations and cytogenetic risk analysis indicated a non-high-risk SPB. The patient was given localized radiation therapy at 57 Gy in 27 fractions. Her neurologic complaints were subsequently relieved, and mobility was restored 7 days postoperatively.

Conclusions: No consensus on the appropriate surgical approaches and perioperative strategies for spinal SPB exists. Surgical intervention is recommended when vertebral instability is evident, followed by radiation therapy to minimize local recurrence and/or progression to multiple myeloma. The use of 3D modeling for preoperative planning improves intraoperative accuracy and avoids iatrogenic injuries to vital anatomic structures. Customized 3DP-PSI to restore atlas stability is an effective option for the treatment of spinal SPBs.