Primary diffuse leptomeningeal gliomatosis: An autopsy case report

Abstract

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare condition, characterized by infiltration of the meninges by glial cells without evidence of the primary tumor in the brain or spinal cord parenchyma. Glioma arising primarily from the leptomeninges is extremely rare and often diagnosed only in post mortem examination and the diagnosis may be missed in meningeal biopsy. We describe a young female who presented with symptoms of raised intracranial pressure with imaging evidence of diffuse leptomeningeal enhancement in whom autopsy confirmed the diagnosis of PDLG. Our case illustrates the diagnostic difficulties in making the pre-mortem diagnosis even with multiple cerebrospinal fluid cytologies and leptomeningeal biopsy.

Keywords: Chronic meningitis; leptomeningeal gliomatosis; meningeal biopsy; neoplastic meningitis.

Figure 1

(a) T1 weighted axial magnetic resonance imaging brain with gadolinium contrast showing diffuse, thick leptomeningeal enhancement (black arrow) with normal brain parenchyma and ventricles and (b) thick nodular leptomeningeal enhancement in cerebellomedullary cistern (black arrow)

Figure 2

The base of the brain seen to be plastered by thick whitish exudative material encasing the vessels of circle of Willis and basal cranial nerves

Figure 3

(a) Tumor cells seen over the surface of cerebellum (H and E, ×40) (b, c) Tumor cells showing pleomorphism, atypical mitosis, giant cells and fibrillary background (H and E, ×400) (d) Foci of microvascular proliferation (H and E, ×200)

Figure 4

Immunohistochemical profile of tumor with cytoplasmic positivity for glial fibrillary acidic protein (GFAP) (a) Vimentin (b) epidermal growth factor (EGFR) (c) GFAP×40, Vim, EGFR HRP×200 (d) P53 showing nuclear positivity in almost all the tumor nuclei. (p53×200)