Spinal dumbbell tumors: An analysis of a series of 118 cases

Object. The authors analyzed a series of 118 cases of spinal dumbbell tumors to elucidate the feature of the tumors. Methods. Of 674 cases of spinal cord tumors, the incidence of dumbbell tumors was studied. The tumors were analyzed, and the authors focus on the distribution of age and sex, the pathological diagnoses, their locations, Eden classification, and the surgical methods used. Results. The incidence of dumbbell tumors was 18%. The mean patient age was 43 years, which was younger than that for all spinal cord tumors (mean 50 years). There were 11 patients younger than 10 years of age. The rate of dumbbell tumors in the cervical spine was significantly higher than that of all spinal cord tumors. Fifteen (18%) of the 81 schwannomas were observed in the C-2 nerve root, thus having a higher incidence than those in the other nerve roots. In 99 cases (84%), the tumors were removed through a hemilaminectomy with or without a facetectomy and posterior fusion. Of 118 cases, 69% of the tumors were schwannomas, and malignant tumors were found in 10 cases (8.5%). Seven (64%) of 11 patients younger than 10 years of age had malignant tumors. Three patients older than 10 years of age had malignant tumors, thus accounting for 2.8% of the 107 older patients. Conclusions. The incidence of dumbbell tumors was 18%, and they are not uncommon. Malignant dumbbell tumors were more common in children younger than 10 years of age than in older patients.