Primary spinal paragangliomas: a clinicopathological and immunohistochemical study of six cases

Spinal paragangliomas are uncommon neoplasms and subject of much debate regarding the factors governing their biological behaviour. We describe the clinicopathological and immunohistochemical (IHC) features of six cases of spinal paraganglioma. The mean age of patients was 40 years (range 20-60 years) with a male to female ratio of (2:1). Majority presented with low backache, sphincter disturbances and sensory symptoms. All tumors were intradural in the cauda region one of them extending to the filum. Only one showed focal extradural extension on microscopy. Gross total resection of tumors was possible in all cases. Histologically four showed classical 'zell-ballen' pattern and two revealed an ependymal morphology. On immunohistochemistry, in all the six cases the chief cells were intensely labeled by antibody to chromogranin but not for GFAP while staining for synaptophysin was less intense and variable in five. Sustentacular cells in all cases showed strong expression for S-100 protein and chief cells were stained light in three cases. Low MIB-1 labeling index of 0.01-2% was noted in five cases and in the sixth it was 5%. None of the tumours recurred. Immunohistochemistry assisted in differentiating these relatively benign neural crest tumours from the more aggressive spinal ependymomas.