Diffuse Leptomeningeal Glioneuronal Tumour: An Intriguing Case Report of an Adult Patient with a Previous Optic Astrocytoma

Diffuse leptomeningeal glioneuronal tumour (DLGT) represents a rare type of neoplasm with a limited number of cases and an ambiguous prognosis. It is mainly diagnosed in children, more often in boys. The clinical presentation depends on the area of the central nervous system involved. The diagnostic process must be extremely broad. Currently, no therapeutic guidelines exist. In this report, we present a case of a 26-year-old man diagnosed with DLGT, who at the age of 10, had a pilocytic astrocytoma (PA) that was surgically removed and was afterwards treated with radiotherapy. After 16 years, his neurological condition deteriorated and an extensive diagnostic process was conducted, including molecular genetic testing using the next generation sequencing (NGS), that led to the diagnosis of DLGT. To our knowledge, we present the first reported case of a DLGT, diagnosed in an adult, who as a child was treated for a PA, and was not a case of a malignant transformation, but rather a case of two primary tumours of the central nervous system, in whom neurofibromatosis was excluded.