Paragangliomas of the cauda equina - Imaging features with radiologic-pathologic correlation

Purpose: To determine the imaging characteristics of cauda equina paragangliomas through radiologic-pathologic correlation, The current radiologic, neurosurgical, and pathologic literature on this rare tumor also is reviewed and theories regarding their development are presented, Methods: Twenty-seven cases of intradural spinal paragangliomas submitted to our institution between 1980 and 1995 were evaluated and 11 cases with imaging studies were selected for review, Clinical data, imaging features, surgical findings, and pathologic findings in these cases were analyzed, Results: All 11 cases were located between L1 and L5 and occurred as extramedullary lesions in direct association with the filum terminale or the conus medullaris, Patients ranged in age from 33 to 67, and there was no gender predilection. Presenting signs and symptoms were typical for mass lesions in this region, but were nonspecific, No patients exhibited symptoms due to neuropeptide secretion, Imaging studies showed oval or lobulated masses with dense contrast enhancement, Prominent flow voids suggesting vascular structures were seen in 6 of 9 cases. Tumors ranged in size from 2-9 cm. Gross pathologic features included prominent arterial pedicles as well as dilated draining veins in 8 of 10 cases, Gross or microscopic areas of hemorrhagic necrosis were seen in 9 of 10 cases, Initial diagnosis of ependymoma was made in 6 of 10 cases based on either frozen section or standard histologic preparations, Immunohistochemical analyses where available showed chromogranin, serotonin, and NSE positivity, GFAP stains were negative in all cases, Conclusions: Paragangliomas of the cauda equina share pathologic and immunohistochemical features with extraadrenal paragangliomas found elsewhere in the body, Clinically distinct is the nearly universal lack of clinically significant neuropeptide secretion. Radiologic, histologic, and clinical features in the patients in this study and in previously reported cases are relatively nonspecific and overlap with other tumors found more commonly in this location, such as the myxopapillary ependymoma.