2026 Volume 13 Pages 7-11
Solitary plasmacytoma is a hematologic malignancy in which about 50% of cases progress to multiple myeloma within 10 years. Local radiation therapy is effective for solitary plasmacytoma treatment, but there are cases of spinal cord paralysis due to osteolytic pathological fractures in the spine. Here, we report a 63-year-old male with spinal cord injury caused by pathologic fracture progression after radiotherapy. A 63-year-old male presented with neck pain and left hemiplegia. Imaging studies revealed a pathological fracture of the C5 vertebral body, and biopsy confirmed the diagnosis of solitary plasmacytoma. Radiation therapy temporarily improved symptoms, but progressive quadriplegia developed 2 months later. Cervical spinal cord compression due to an additional vertebral bone fracture was confirmed. Aggressive lesionectomy and fixation using simultaneous anterior and posterior combined approaches were performed. Postoperatively, paralysis completely recovered. No local recurrence or transition to multiple myeloma was observed even after 7 years of follow-up at age 70. Surgical treatment may be effective for spinal cord injury associated with pathologic fracture progression after radiotherapy for solitary plasmacytoma.
Solitary plasmacytoma (SP) is a hematologic malignancy presenting as a single mass of monoclonal plasma cells that can transform into multiple myeloma (MM) in approximately 50% of cases within 10 years.1) SP is an osteolytic tumor that occurs in the axial skeleton, with the thoracic spine being the most common site, while the cervical spine is rare.2)
We report a case of progressive cervical myelopathy due to a pathological fracture after radiation therapy for cervical SP, in which a combined anterior and posterior one-stage surgery resulted in a favorable outcome.
A 63-year-old man presented with neck pain and left hemiparesis. Cervical magnetic resonance image (MRI) showed a high-intensity lesion on T2-weighted images of the C5 vertebral body, which was diagnosed as a pathological fracture (Fig. 1A and B). A biopsy was performed, and the diagnosis of SP was confirmed. Two months after diagnosis, radiation therapy (40 Gy/20 Fr) was administered, and the symptoms tended to improve. One month after the radiation therapy, the neck and shoulder pain recurred, and quadriplegia gradually progressed, making it difficult for him to walk independently. The general hospital determined that further treatment would be difficult, and the patient was referred to our outpatient clinic in a wheelchair due to his progressive cervical myelopathy. Cervical MRI and 3-dimensional computed tomography (3D-CT) showed further collapse of the C5 vertebral body and severe compression of the spinal cord (Fig. 1C-H). We performed emergency surgery consisting of total lesionectomy, including C5 corpectomy and artificial vertebral body replacement with plate fixation via a retropharyngeal route (Fig. 2A and B). On the same day, with the patient in the prone position, a C5 laminectomy and posterior fixation were performed (Fig. 2C and D). Excellent cervical alignment was confirmed during the operation (Fig. 2E-G). Histopathological examination was consistent with SP (Fig. 3A-E). Three months after surgery, the neurological symptoms had completely recovered. No recurrence was observed on cervical MRI, X-ray, or 3D-CT even 7 years after the operation (Fig. 4A-C). In addition, blood and urine tests and systemic examinations showed no abnormal findings.
Initial cervical MRI showed C5 pathological fracture with T2 WI high intensity (A, B). Exacerbation cervical MRI (T2WI) showed collapsed vertebrae at C5 with ventral compression of the spinal cord (C, D). Enhanced MRI showed C5 paravertebral enhancement (E, F). 3D-CT findings collapse vertebrae at C5 in the sagittal image and osteolytic change in the axial image (G, H).
3D-CT: 3-dimensional computed tomography; MRI: magnetic resonance imaging; WI: weighted image
Intraoperative views showed after C5 corpectomy (A), and artificial vertebral body replacement and plate fixation (B). Intraoperative views showed after C5 laminectomy (C), and posterior screw and rod fixation (D). Intraoperative X-ray (E) and postoperative X-rays (F, G).
H&E staining is shown. Original magnification ×200 (A), ×400 (B); There are numerous plasma cells with monotonous proliferation, eccentric nuclei, and clear perinuclear circles. Immunostaining revealed positive results for CD138 (C), and the number of κ-positive cells was greater than the number of λ-positive cells (D, E), indicating a diagnosis of plasmacytoma.
H&E: hematoxylin & eosin
MRI at 7 years after surgery shows no spinal cord compression and no local recurrence (A). Cervical X-ray and 3D-CT at 7 years after surgery show bone union and no displacement of instruments (B, C).
3D-CT: 3-dimensional computed tomography; MRI: magnetic resonance imaging
In the review of spinal SP, the condition was found to be more common in men over the age of 50, and its incidence increased during the study period.3) The median survival was 6.08 years, with a 5-year survival rate of 56.1% and a 10-year survival rate of 36.7%.3) Unfavorable prognostic factors included advanced age and the absence of radiotherapy.3) After 3 years, 10.1% of SP patients showed progression to MM. Patients aged 70 years and older were more likely to transition to MM, which was not associated with surgical treatment.3) Radiation therapy is considered effective and is recommended with or without surgical treatment.1,3) Surgical treatment is often performed in cases with pathological fractures of the spine that cause spinal cord injury.4) However, in cases of progressive quadriplegia due to recurrent pathological fractures after radiotherapy, surgical treatment is often avoided because such cases are considered end-staged.
Radiation therapy remains the recommended treatment. However, Ouyang et al.5) reported that osteolytic changes were observed in 2 cases (5.2%) and mild osteoplastic changes in 41% to 53.8% of 39 patients after radiotherapy. In a comparison between radiation therapy alone and surgery combined with radiation therapy, the survival rate was lower with combined therapy, but the transition to MM was less frequent in younger patients (under 45 years of age) who underwent surgery.6)
There are a few reports of cases treated with surgery alone, which showed poor outcomes. von der Hoeh et al.7) reported a case of lumbar SP undergoing 2-stage anterior corpectomy after posterior fusion surgery. Sakhrekar et al.8) reported a case of recurrent pathological fracture in a thoracic SP lesion after decompression surgery, in which single-stage anterior and posterior surgery was subsequently performed. Good results have been reported with posterior fusion combined with radiotherapy at the craniocervical junction.9) For spinal pathological fractures due to hematologic diseases, combined anterior and posterior decompression and fixation using total spondylectomy are effective.10)
Aggressive surgical treatment is effective for spinal cord injury associated with pathologic fracture progression after radiotherapy for cervical SP. Long-term functional prognosis can be expected for spinal SP when surgical treatment is combined with radiotherapy.
All authors have no conflict of interest.
Informed consent was obtained from the patient.
