Contrast MRI Findings for Spinal Schwannoma as Predictors of Tumor Proliferation and Motor Status.
METHODS
Retrospective analysis.


OBJECTIVE
The goal of this study was to examine the relationship of the proliferation potency based on the MIB-1 index and motor status with features of T2-weighted images (T2WI) and contrast T1-weighted images (T1WI) of spinal schwannoma.


BACKGROUND
Spinal schwannomas account for 55% of spinal tumors, but the relationship of cellular proliferation with MRI findings for spinal schwannoma is unknown.


METHODS
The subjects were 48 patients (22 males and 26 females) with spinal schwannoma who were classified into three subgroups: iso/homo, high/rim, and hetero/hetero, based on T2WI/contrast T1WI. A retrospective analysis of tumor size and MIB-1 index was performed in the context of these MRI findings. Intraoperative findings and pre- and postoperative motor performance were also examined.


RESULTS
The average tumor size was 32.4 mm (range 10-130 mm) and the average MIB-1 index was 3.8% (range 1-12). In the three subgroups, there were no significant differences in sex, age, duration of disease, tumor lesion, and dumbbell type. In the hetero/hetero group, the tumor size was significantly greater and the MIB-1 index was significantly higher (both P < 0.05), than the other two groups. The tumor adherence rate was significantly higher for hetero tumors (P < 0.05) and preoperative paralysis was more common in cases with tumor adhesion. The rate of paralysis improvement at 1 month was significantly lower for hetero tumors, but all cases had improved at 6 months.


CONCLUSIONS
Contrast T1WI MRI was useful for prediction of the proliferative activity and growth of spinal schwannomas, which are associated with increased tumor size and adhesion. A heterogeneous pattern on contrast T1WI indicated an increase in size and adhesion of the tumor. This pattern reflected the preoperative motor status and postoperative motor recovery.


METHODS
4.
Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Aichi, Japan.
Kazuyoshi
K
Kobayashi
Shiro
S
Imagama
Kei
K
Ando
Tetsuro
T
Hida
Kenyu
K
Ito
Mikito
M
Tsushima
Yoshimoto
Y
Ishikawa
Akiyuki
A
Matsumoto
Masayoshi
M
Morozumi
Satoshi
S
Tanaka
Naoki
N
Ishiguro
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009442:Neurilemmoma / Q000000981:diagnostic imaging* / Q000601:surgery; D012189:Retrospective Studies; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult