Subependymal nodules-subependymal giant cell astrocytoma complex in children with tuberous sclerosis

The object of this paper is to describe the imaging and clinical characteristics of subependymal nodule (SN) - subependymal giant cell astrocytoma (SGCA) complex in tuberous sclerosis and analyze its evolution in order to attempt early detection and the prevention of intracranial hypertension. We evaluated 22 patients with the pathological diagnosis of SGCA. The diagnosis was made at a median of 10.1 years old. We were able to observe the evolution of SN to ASGC: these SN were localized adjacent to the foramen of Monro and with time they underwent an important development with intense contrast enhancement and hydrocephalus. The acceleration in SN growth and its "transformation" into SGCA occurred at an average of 10 years of age, with a mean diameter of 9 mm. No SN located far from the foramen of Monro evolutioned to SGCA. Fifteen patients (68%) were operated with symptoms of intracranial hypertension. Average age at surgery was 10.8 years old. Six patients presented visual deficit and in these, the average diameter of the tumor was 31.5 mm, a high value when compared to 18.7 mm in the patients without visual deficit. The imaging and clinical follow-up of any subependymal lesion close to the foramen of Monro will permit, at a presymptomatic stage, an anticipation of surgical treatment thus reducing intracranial hypertension incidence. Prospective studies could determine whether the SN-SGCA complex corresponds to the same entity in distinct evolution stages or to two lesions with different growth potential.