Subependymal Giant Cell Astrocytoma without Clinically or Genetically Identifiable Tuberous Sclerosis Complex: A Case Report

Abstract

Background: Subependymal giant cell astrocytoma (SEGA) is a World Health Organization grade I tumor most commonly located in the lateral ventricles near the foramen of Monro. They are primarily associated with tuberous sclerosis complex (TSC), an autosomal dominant inherited condition that leads to a variety of tumors throughout the body. TSC must be diagnosed via either genetic criteria or clinical criteria. Cases of SEGA in patients without both genetically or clinically identifiable TSC are scarce, with only two instances identified of those genetically screened in the literature. We describe what we believe is only the third such case, a 22-year-old patient with no other clinical or genetic indicators for tuberous sclerosis. Case Description: The patient is a 22-year-old Caucasian female who experienced progressive symptoms of headaches, tinnitus and visual obscuration. A magnetic resonance imaging study of the brain revealed a homogeneously enhancing mass in the right lateral ventricle with obstruction of the foramen of Monro. The patient underwent a right frontal craniotomy for transcortical-transventricular resection of the mass. Histologic examination of the tumor revealed a diagnosis of SEGA. Germline genetic tests for both TSC1 and TSC2 were negative, and no additional clinical features were present. The patient was thus not felt to meet the criteria for a diagnosis of TSC based on the absence of clinical features, family history, and negative genetic testing. Conclusion: Although a rare phenomenon, SEGA should remain on the differential diagnosis for patients with newly found periventricular tumors and absence of TSC clinical features.