Multicentric extramedullary myxopapillary ependymomas: Two case reports and literature review.

BACKGROUND: Ependymoma has been described typically as an intramedullary tumor derived from ependymal cells. Intradural extramedullary presentation is rarely described and almost always as a unique lesion. Myxopapillary ependymoma is a histological variant that distinguishes from the ordinary type of ependymoma because of its generally better prognosis. We present two cases of multicentric extramedullary myxopapillary ependymomas. CASE DESCRIPTION: Case 1 was a 30-year-old man with progressive paresthesia and paresis in the lower limbs, urinary sphincter disturbances, gait instability, ataxia, and chronic low back pain with multiple intradural extramedullary lesions at C2-C3, D2-D4-D5, and D12-L1. Case 2 was a 32-year-old man, presented with low back pain and mild paresthesia in the right lower limb. Magnetic resonance imaging (MRI) showed multiple intradural extramedullary lesions with homogeneous enhancement after gadolinium injection at C7, D2, D4, D5, D8, D10, D11, L1, L3, L5, S1, and S2. Complete tumor resection of the approached tumors was archived in both cases. Histological studies confirm myxopapillary ependymomas. Patient's neurologic outcome was good and no residual tumor was present at MRI control at 10 years in case 1 and 12 months in case 2. CONCLUSIONS: We report the first two cases of multicentric extramedullary myxopapillary ependymomas, this etiology must be taken into account in the differential diagnosis of intradural extramedullary tumors.

Epilepsy due to a temporal ganglioglioma and its subsequent malignant transformation into a primitive neuroectodermal tumor.

BACKGROUND: Gangliogliomas (GGs) are rare brain tumors, and their malignant changes are still less frequent. In these cases, almost always the malignant component is the glial one. However, there are few cases in which the neuronal component exhibits malignant transformation. CASE DESCRIPTION: We described a case of a 14-year-old male patient who started with seizures and 5 years later, its frequency was almost daily despite being treated with several antiepileptic drugs. Magnetic resonance imaging showed a nonenhancing lesion located at the right inferior temporal gyri. He underwent surgery, and the tumor was completely removed. Histological diagnosis was GG. He had no seizures anymore, but 3 years later, the tumor recurred as a giant heterogeneously enhancing space-occupying mass within the right temporal lobe. A second surgical resection was performed. Histological diagnosis was a primitive neuroectodermal tumor (PNET). One month and a half later, the tumor has recurred again. He and his family decided not to undergo another operation, so he was referred to the radiotherapy department. CONCLUSION: As in this patient, GGs may recur as a primitive neuroectodermal tumor, likely because both types of neoplasm form part of the same heterogeneous group of brain tumors which contains neuronal components, but on the other side of the malignancy spectrum.