81 year-old male with confusion and weakness

Glioblastoma, the most common primary brain tumor, is a highly infiltrative, malignant astrocytic neoplasm that demonstrates a wide spectrum of morphologic heterogeneity. Cases with a primitive neuroectodermal tumor (PNET)-like component are rare, but are being increasingly recognized and studied. The primitive component typically shows immunohistochemical features that are indicative of potential for divergent differentiation along glial and neuronal pathways; when present, the entire neuraxis may be at risk for involvement, portending a particularly poor prognosis. Recently, data from the largest case series studying malignant gliomas with a PNET-like component suggest that the primitive component likely arises from the malignant glial component. This report presents an example of glioblastoma with a prominent primitive neuroectodermal-like component in an 81 year-old male who, during the course of concurrent chemotherapy and radiation therapy, died five weeks following initial diagnosis.