Nondura-based clear cell meningioma of the cauda equina in an adult

Abstract

Clear cell meningioma (CCM) is a rare variant of meningioma with a worse prognosis than other types of meningioma. The World Health Organization (WHO) classification of tumors of the central nervous system recognizes CCM as a meningioma variant, WHO grade II [1]. Histologically, CCM is composed of polygonal cells with a clear, glycogen-rich cytoplasm, vague whorl formations, and stromal deposits of collagen bundles. Since its first description by Scheithauer [2], CCM has been reported most frequently in spinal/intradural (thoracic and lumbar), cerebellopontine angle, and supratentorial locations, with the lumbar region and cerebellopontine angle being the most common [3]. Pediatric recurrence of these tumors is high; for adult cases secondary management strategies, including repeated resection with or without secondary radiation therapy, are controversial. Epstein et al. [4] advocated gross total resection of lumbar tumors as the current optimum management in adults, with radiation therapy reserved for secondary recurrences. In addition, although most meningiomas are based in the dura, on the basis of Pubmed from 1990 to 2011 years, 12 cases of nondura-based CCM of the lumbar spine and cauda equina have been reported [5–15]. Here, we report the case of a 43-year-old man with nondura-based CCM of the cauda equina without any local recurrence 7 years after resection.