Cauda equine ganglioneuromatous paraganglioma with positive cytokeratin and occult cleft spine: a case report and review of the literatures

Abstract

Objective To investigate the clinical manifestations and pathological features of paraganglioma of cauda equine. Methods The clinical manifestations, histopathology and immunophenotype features were studied in one rare case of cauda equine paraganglioma with ganglioneuroma differentiation, positive cytokeratin (CK) and bifid occult spine. Related literatures were reviewed. Results The patient was a 47-year-old male. Numbness of the right sole lasted for 2 months, then developed to anaesthesia of two legs. The MR image demonstrated a mass in L4-S1. In operation, it was found that the irregular tumor was 5 cm × 3 cm × 3 cm in size, yellow-white in color, with abundant blood supply, attached to the caudal nerve root and varied in consistency from soft to hard. Cauda equine and nerve root were compressed. The histopathological examination revealed the tumor presented a biphasic tissue pattern with paraganglioma and ganglioneuroma-components. The cells of paraganglioma were arranged in solid sheets, or organoid growth pattern，or carcinoid patterns, or pseudorosette pattern, or hemangio-perithelioma patterns or papillary patterns. The other component presented ganglioneuroma in a solid pattern. Two components existed separately or mixed together. Immunohistochemical examination found cytokeratin, α-synuclein and chromogranin A (CgA) were positive in the paraganglioma area. Some paraganglioma cells expressed S-100 protein-like sustentacular cells. Ki-67 antigen labeling index was less than 5%. α-synuclein, neuronspecific enolase and CK were positive, and neuronal nuclei (NeuN) antigen was negative in the ganglioneuroma cells. Conclusion Paraganglioma is an uncommon benign primary tumor of cauda equine characterized by a slow growth like ependymoma pattern with male predominance. This case is very rare because of the coexistance of ganglioneuroma, multi-histological and cytological morphology, strong positive CK expression and occult cleft spine. The expression of CK may be an important feature of paraganglioma of cauda equine.

DOI：10.3969/j.issn.1672-6731.2011.06.003