Benign notochordal cell tumor: a retrospective study of 11 cases with 13 vertebra bodies.

PURPOSE To analyze the clinical data, MRI, pathological diagnosis, treatment and long-term effects of benign notochordal cell tumor (BNCT), a newly described novel spine tumor. METHODS We retrospectively studied 11 patients' clinical data of the above. RESULTS The ratio of males to females was 4:7, and the average age was 49.2 years (range, 18-74 years). Cervical vertebra (5; 38.5%) and thoracic vertebra (5; 38.5%) were the most frequent site followed by the lumbar vertebra (3; 23%). Pain was the main symptom except case 2 who were diagnosed accidently because of prostate cancer. The mean delay from first clinical symptoms to diagnosis was ranged from 2 months to 20 years. MRI showed all BNCTs were osteolytic lesions with hypointense on T1-weighted sequences, hyperintense on T2-weighted sequences. There were 4 vertebral bodies with wedge fracture. There were two cases that had two noncontiguous vertebral bodies with BNCT. In histology, marrow replacement was noted by multivacuolated physaliphorous cells immunoreactive for CK, EMA and S100 protein. All 10 cases except case 2 had vertebral reconstruction and fixation with different methods. Of the 11 patients, 9 had full follow-up data which showed no evidence of recurrence or metastasis without further treatment. CONCLUSION Noncontiguous multi-centricity BNCTs are rare. No specific vertebrae are more frequently involved. Once BNCT is diagnosed by pathology, the surgical intervention is necessary for the patients with obvious clinical symptoms although it is benign. There is no evidence of BNCT recurrence or metastasis.