Primary intracranial peripheral primitive neuroectodermal tumor: lessons from an exceptionally rare neoplasm. Illustrative case.

BACKGROUND: The primary intracranial peripheral primitive neuroectodermal tumor (pPNET) is a lesion subtype within the Ewing sarcoma family of tumors. pPNETs are extremely uncommon pathologies, accounting for 0.03% of intracranial tumors and 1% to 2% of Ewing sarcoma cases. Given its histological aspect similar to other highly proliferative malignant neuroectodermal neoplasms, pPNET merits extensive workup for accurate diagnosis and treatment. OBSERVATIONS: A 36-year-old male presented to the emergency department with a 1-year history of headaches in the right frontoparietal area, generalized tonic-clonic seizures, and a history of the resection of a tumor labeled as a meningioma 5 years before admission. He was neurologically intact. Brain magnetic resonance imaging revealed a heterogeneous focal lesion of 25 × 35 × 23 mm with a necrotic center and neoformative appearance in the right frontal cortex. The patient underwent multimodal treatment with gross-total resection, radiotherapy, and chemotherapy. Histopathological examination results supported the diagnosis of pPNET. At the 2-year follow-up, the patient had no new-onset symptoms, and brain imaging revealed absent signs of tumor recurrence. LESSONS: The present case describes an extraordinary pPNET case, initially confounded as a clear cell meningioma. Managing pPNET requires thorough investigation, careful differentiation from similar neuroectodermal lesions, and multimodal treatment to improve the patient's prognosis.

Abordaje temporopolar para la cirugía de aneurismas intracraneales de la circulación posterior: Informe de 2 casos / Temporopolar approach to intracraneal aneurysms surgery of the posterior circulation: to cases report

Los aneurismas intracraneales de la circulación posterior representan un reto para la neurocirugía contemporánea y para la neurorradiología intervencionista, debido a la complejidad anatómica de su topografía que predispone a la aparición de complicaciones. La oclusión endovascular representa la opción más acertada para el tratamiento de estas lesiones, pero al no existir una cobertura adecuada para todos los pacientes, la microcirugía representa una alternativa para el manejo de los pacientes con esta compleja enfermedad. En el presente trabajo se presentan dos casos intervenidos quirúrgicamente, uno con un aneurisma del tope de la basilar y otro con uno de la arteria cerebelosa superior izquierda, en los que se utilizó un abordaje temporopolar descrito por Sano, con resultados satisfactorios. Se concluye que este abordaje representa una alternativa adecuada al resto de las técnicas usadas para el tratamiento quirúrgico de estas lesiones

Intracranial aneurysms of the posterior circulation represent a challenge for contemporary neurosurgery and interventional neuroradiological procedures due to the anatomical complexity of its topography that predispose on the occurrence of complications. The endovascular occlusion represents the best option for the treatment of these injuries, but at not existing a coverage suitable for all patients, microsurgery continues representing an alternative for the management of patients with this complex disease. In this paper we present two cases operated, one with a basilar tip aneurysms and another one in the left superior cerebellar artery in which a temporopolar approach described by healthy, with successful results was used. We conclude that this approach represents an alternative to the rest of the techniques used for the surgical treatment of these injuries