Retinal Reactive Astrocytic Tumor (Focal Nodular Gliosis): The Entity Also Known as Vasoproliferative Tumor.

ditions including retinopathy of prematurity, retinal detachment surgery, uveitis, sickle cell disease, and others. Shields and co-workers [11] described this condition as “presumed acquired retinal hemangioma” and finally as “vasoproliferative tumor” [12] , a name that persists in the current literature and clinical practice. Recent histopathologic analyses have shown that the vascular component of the tumor is minor and the glial/astrocytic component predominates, even in early lesions [1, 2, 13–16] . These findings and their interpretations [17, 18] have led to some controversy centering in the desire to preserve the use of clinical appearances as the best way to define the lesion. There is a concomitant resistance to more refined cytometabolic [13] molecular genetic characterization [1] – ideally correlated with clinical data. Based on histologic, immunohistochemical, and molecular diagnostic findings, this tumor was called “reactive retinal astrocytic tumor” [1] . In fact, when experienced neuropathologists reviewed the histopathology of this tumor, none thought that it was vascular in nature; all interpreted these to be primary glial/astrocytic tumors and wondered if they could even be low-grade malignant astrocytomas. Studies of this tumor included a lack of BRAF-KIAA gene rearrangement and IDH1-R132H mu