Primitive neuroectodermal tumor presenting with diffuse leptomeningeal involvement in a 55-year-old woman: a case report and brief summary of current diagnostic tests and treatment

Abstract

Primitive neuroectodermal tumors (PNETs) are typically present as masses in children and adolescents, but rarely in adults. Diagnoses, management strategies, and prognostication factors are not well established in adult cases of PNETs. We describe the case of a central nervous system PNET diagnosed in a 55-year-old woman presenting with a sudden onset of symptoms consisting of increased intracranial pressure and findings of diffuse leptomeningeal enhancement and a small medullary lesion seen on MRI. Amongst the small database of PNETs diagnosed in adults, our case report stands out as one of few cases describing a primarily leptomeningeal PNET diagnosed on biopsy. We also review the literature on PNETs presenting with diffuse leptomeningeal disease and the treatment of PNETs in the adult population.

Keywords: Adult primitive neuroectodermal tumor; Leptomeningeal involvement; Primitive neuroectodermal tumor.

Fig. 1

a Axial FLAIR image shows increased signal intensity of the subarachnoid spaces at the level of the basal cisterns. b Postcontrast axial T1-weighted sequence shows the corresponding leptomeningeal enhancement in the basal cisterns.

Fig. 2

Sagittal T1-weighted sequences of the spine after gadolinium injection demonstrate diffuse leptomeningeal enhancement along the brainstem, and along the spinal cord and proximal cauda equina nerve roots.

Fig. 3

Axial T2-weighted (a) and axial FLAIR (b) images demonstrate an ill-defined expansile intra-axial lesion in the left posterolateral aspect of the medulla. Note the increased CSF signal intensity within the premedullary cistern.