Malignant glioma-primitive neuroectodermal tumor recurring as PNET-like only subdural collection: Case report

BACKGROUND: Histologic variants of conventional glioblastoma are rare clinical entities. In recent years, an aggressive variant termed malignant glioma with primitive neuroectodermal tumor components (MG-PNET) has been described in adults. In addition to the rarity of supratentorial primitive neuroectdoermal tumors (sPNET) in adults, MG-PNET can present with unique radiographic features. CASE DESCRIPTION: We report the case of a 42-year-old male who presented with headaches and vision changes. Magnetic resonance imaging (MRI) of the brain revealed a large right frontal lesion. He underwent craniotomy with pathology demonstrating glioblastoma WHO grade IV, with primitive neuroectodermal tumor-like components (MG-PNET). Seven weeks later the patient represented with worsening headaches and left-hand weakness. MRI brain revealed a diffusion restricting subdural collection overlying the prior craniotomy site. Biopsy revealed PNET-like recurrence of the previously treated MG-PNET. CONCLUSION: In addition to histologic deviation, MG-PNET can present with variable radiographic findings on MRI and a clinical course distinctive from traditional glioblastoma. The hypercellular nature of this lesion can present as a diffusion-restricting lesion.