Volumetric growth analysis of an insular dysembryoplastic neuroepithelial tumor over a 10-year follow-up

BACKGROUND: Dysembryoplastic neuroepithelial tumors (DNETs) are benign tumors characterized by a cortical location; they result in symptoms of drug-resistant partial seizures in children. The development of DNETs is poorly understood because most of them are resected immediately upon diagnosis without any observation period owing to the intractable seizures. CASE DESCRIPTION: We report the first DNET case with the growth rate analyzed in the natural course of development for a period of 10 years. The patient was a right-handed man who was initially referred to another hospital with mild head injury when he was 8 years old. A tumor located in the right insular cortex was incidentally detected on magnetic resonance imaging (MRI) and followed-up with annual MRI for 10 years. CONCLUSION: In this case, the volume of the DNET increased in direct proportion to the length of time in its clinical course. The tumor doubling time was approximately 10 years. This case suggests DNET is a slow-growing but not stable tumor.