Primary spinal leptomeningeal gliomatosis in a 3-year-old boy revealed with MRI and FDG PET/CT mimicking tuberculosis meningitis

Abstract

A 3-year-old boy was referred to neurologist for inward devition of his left eye, weakness, lack of appetite, headache and ehavioral change. On physical examination, the findings of ilateral abducens nerve paralysis were noted. Cranial magnetic esonance imaging (MRI) revealed diffuse leptomeningeal contrast nhancement at the supra-infratentorial regions predominantly nvolving the basal cisterns and also hydrocephalus and initially uggesting basilar meningitis. Cerebrospinal fluid (CSF) studies howed normal glucose and elevated protein levels but no tumor ells. No growth was detected in any of the bacterial cultures ncluding acid-resistant bacteria. The patient was started on oral nti-tuberculosis medication and corticosteroid treatment with he presumed diagnosis of tuberculosis meningitis and a ventricuoperitoneal (VP) shunt was inserted due to hydrocephalus. After months of treatment, the patient was re-admitted to hospial with vomiting, convulsion and confusion. Cranial MRI showed he similar findings to previous one, and spinal MRI depicted iffuse leptomeningeal contrast enhancement as well as microystic changes along the spinal cord (Fig. 1). Histopathology of the ural biopsy material revealed widespread glioma infiltration of he subarachnoid space suggestive of leptomeningeal gliomatosis. his patient with unknown primary was referred for FDG PET/CT. nder child sedation, brain and whole body non-contrast enhanced ET/CT images were obtained 90 min after the intravenous injecion of 148MBq (4mCi) 18F FDG using a Biograph 6 PET/CT. The can depicted slightly increased FDG uptake (SUVmax 2.1)along the pinal cord without any other FDG-avid primary tumor. The patient as started on chemotherapy including vincristine and carboplatin Figs. 2 and 3). His symptoms were relieved after completion of hemo. Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare isease thought to arise from isolated astrocytic cell nests also nown as heterotropic neuroglial tissue within the leptomeninges HLNT) in the subarachnoid space. The HLNT can transform into two