Desmoplastic infantile ganglioglioma/astrocytoma: expanding the molecular and morphological spectrum with a novel BRAF fusion

Abstract

Background Desmoplastic infantile ganglioglioma/astrocytoma (DIG/DIA) is a rare, low-grade tumor of infants. They are usually composed of a mixed astrocytic and neuronal component with desmoplastic stroma and embryonal-looking areas. Despite some recent reports, clinical, morphological and molecular features of DIG/DIAs are still not well characterized. Here, we present a series of 8 DIG/DIA cases.Methods Hacettepe University and Koc University Hospital, Departments of Pathology, databases were screened for DIG/DIA. Eight patients were identified. All the slides were reevaluated, and patients' clinical data were obtained. All cases were tested for BRAF V600 mutation and 3 BRAF V600 wild-type cases were sequenced.Results Median age at the diagnosis was 5.5 months (4-30 months). The female to male ratio was 6:2. Two cases recurred. Four cases showed BRAF p. V600 mutation. Of those BRAF p. V600 wild-type cases, one harbored TMEM106B