Solitary bone plasmacytoma of spine with involvement of adjacent disc space: A case report

Abstract

Rationale: Solitary bone plasmacytoma (SBP) is a rare manifestation of plasma cell tumor. Although axial skeleton is the most frequently affected site of SBP, adjacent disc space involvement is rare. Herein we report a case of SBP in thoracic vertebra with involvement of adjacent disc space.

Patient concerns: A 57-year-old male presented with a 2-year history of intermittent back pain with activity. The patient's back pain intensity with activity was a score of 5 of the 10-point visual analog scale).

Diagnoses and intervention: The patient underwent a posterior fusion procedure from T6 to T10, and an open biopsy of the vertebral lesion confirmed that final diagnosis of SBP. The patient received postoperative radiotherapy with a total of 4000 Gy to the T7-T9 vertebral levels over a 20-day period.

Outcomes: Following radiotherapy, the patient's pain intensity was reduced to the visual analog scale score of 1 at the 6-month follow-up.

Lessons: SBP lacks typical clinical symptoms, and the accurate diagnosis before clinical intervention remains challenging. Due to the disc involvement, SBP often manifests as spinal infection. Hence, differential diagnosis in spinal lesions involving the disc should include SBP.

Figure 1

Lateral spine radiograph demonstrated osteolytic destruction of T7 and T8 vertebral body with intervertebral space stenosis (A). Mid-sagittal CT of thoracic spine suggested slight expansile osteolytic destruction in T8 vertebral body with sclerosis margin, extension to T7 and T9 vertebral body (arrows) and adjacent disk-space destruction (asterisk) (B). The corresponding thoracic spine MRI revealed the lesion exhibiting mildly isointense on T1 weighted image (C), hyperintense on T2 weighted image (D), and intense homogeneous enhancement on T1-weighted post contrast image (E).

Figure 2

Hematoxylin and eosin (H&E) stained biopsy specimen showed a small number of fragments of bone trabeculae and denatured collagenous fibers with inflammatory exudates (100×).

Figure 3

Hematoxylin andeosin (H&E) stained section showed a diffuse monotonous infiltrate of plasma cells (200×).

Figure 4

Immunohistochemical markers were positive for CD38 (A, 200×), CD138 (B, 200×). Lambda was positive (C, 100×). Kappa was negative (not shown).

Figure 5

PET-CT scan showed the hypermetabolic lesion in T7 to T9.

Figure 6

Thoracic spine magnetic resonance imaging at 6 months after radiotherapy showed the lesion was smaller compared to the pre-treatment imaging (A). The lesion exhibiting mildly isointense on T1 weighted image (B). Hyperintense on T2-weighted image.