A diagnostic challenge in a child: a rare brain tumour or tuberculous meningitis

Abstract

A case of non-responding tuberculous meningitis in a 10-year-old male child who was diagnosed and received Anti-Tubercular Therapy twice. After exploring for alternative diagnosis, biopsy was suggestive of DLGNT. High prevalence of tuberculosis in India and similarity in MRI brain findings might have contributed for delay in diagnosis. Leptomeningeal enhancement in Paediatric patients is a common MRI finding associated with numerous conditions including infections, inflammatory process, neoplasms, and post-ictal hyperaemia. Presence of leptomeningeal enhancement along with hydrocephalous in the patients living in developing world are often labelled as tuberculous meningitis. DLGNT is a rare neoplasm, which was previously known as a disseminated oligodendroglia-like leptomeningeal tumour of childhood. DLGNT has been defined as a neuronal/glioneuronal tumour as per the 2021 World Health Organization (WHO) classification of brain tumours.  This tumour may also present with hydrocephalous in initial stages. The confirmatory diagnosis of tuberculous meningitis is often difficult as its clinical features are not very specific. Detection of Mycobacterium tuberculosis in cerebrospinal fluid (CSF) by acid-fast staining, culture, or DNA analysis with polymerase chain reaction (PCR) has low sensitivity. DLGNT needs histologic confirmation through brain biopsy. Although rare, DLGNT should be considered as a differential diagnosis. Especially in children who are solely diagnosed on radiological evidences of tuberculosis. The current case highlights the importance of histologic confirmation through brain biopsy for cases presenting leptomeningeal enhancement in the basal cistern in MRI with equivocal laboratory examinations to explain the aetiology.