Dysembryoplastic neuroepithelial tumor and calcifying pseudoneoplasms of the neuraxis: A collision of two seizure-associated lesions

Dysembryoplastic neuroepithelial tumor (DNET) is a benign glioneuronal neoplasm typically associated with intractable, partial complex seizures in children and young adults. The authors present a case in which a DNET in a 45-year-old male was accompanied by a so-called "calcifying pseudoneoplasm of the neural axis" (CPNA), a rare tumefactive lesion considered reactive in nature. An MRI scan of the brain revealed a right temporal lobe abnormality with characteristics of DNT but no apparent calcification. Histologically, it exhibited classic features of DNET and an overlying meningeal-based, partially ossified, chondrocalcific lesion morphologically characteristic of CPNA. The association of DNET and CPNA has not been previously reported. The literature relevant to these two seizure-associated lesions is reviewed.