Spinal intraosseous schwannoma : a case report and review

Abstract

A case of spinal intraosseous schwannoma (SIS) in the lumbar vertebra is reported. Clinical and radiologic characteristics of 16 reported cases of SIS were reviewed. SIS can be a rare differential diagnosis for intraosseous tumors.

Keywords: Ancient; Intraosseous; Schwannoma; Spinal; Vertebral.

Fig. 1

Preoperative spine computed tomography reveals the completely intraosseous and expansile nature of the tumor.

Fig. 2

T1-weighted, T2-weighted, and contrast-enhanced T1-weighted magnetic resonance imaging of the tumor. The poorly enhanced rim-like T2 high signal intensity areas represent the degenerated portion of the ancient schwannoma. Peripheral enhancement of the degenerative portion is found, and this is the cardinal radiologic characteristic of ancient schwannomas.

Fig. 3

Intraoperative photograph obtained after most of the film-like right L4 vertebral wall was removed by the punch. A friable, soft, and grayish mass with heterogeneity is found.

Fig. 4

After corpectomy and tumor removal, a mesh cage was inserted to the L4 body. Posterior lumbar interbody fusion was performed to the L3 and L5 body.

Fig. 5

Antoni A area (A) and Antoni B area with thrombosed vessels (B), a characteristic of ancient schwannomas (hematoxylin & eosin; ×200).

Fig. 6

Diagrammatic representation of the proposed modified classification of spinal schwannomas Types I to VII. Types I to V are identical to original classification of spinal schwannomas suggested by Sridhar. Types VI and VII are additional types in modified classification of spinal schwannomas (Table 2). Type II is not shown.