RESUMEN
Purpose To investigate clinicopathologic fea-tures of sacral cellular schwanoma and the difference from sacral conventional schwanoma.Methods Eight cases of sacral cellular schwanoma were collected.Microscopic examination and immunohistochemistry were performed for studying the clinical feature,radiologic appearance,pathologic characteristic,immunophenotyping,differential diagnosis and postoperative prognosis.Results There were 5 females and 3 males,whose mean age was 46.4 years.The majority of patients complained of pain in sacrococcygeal region.Radiographically,there was an endosacral or endosacral and presacal mass.Histologically,cellular schwannoma was composed of spindle cells,arranged in interlacing fascicles without nuclear palisading and Verocay bodies.Antoni A and Antoni B were not seen overtly.The destruction of bone was found.Immunohistochemically,tumor cells were diffusely and strongly positive for S-100 protein and vimentin.The mean of Ki-67 index was 6％.Tumor recurrence of 4 cases occurred several years after initial surgical resection.The mean interval to recurrence was 6.5 years.Conclusion Sacral cellular schwanoma is a rare tumor.Compared with sacral conventional schwanoma,it shows different growth pattern and pathologic features.So pathological diagnosis of the tumor should be noted for clinical follow-up and treatment.