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Objective: To compare clinicopathological characteristics of patients with solitary subependymal giant cell astrocytoma (SEGA) at our institution, with those associated to tuberous sclerosis complex (TSC). Methods: It was a descriptive-retrospective study of surgically treated SEGA patients (2013-2022). Demographic and clinical data were obtained. An immunohistochemistry (IHC) panel was applied: GFAP, neurofilaments, hamartin, tuberin, Ki67, nestin, OCT-4, INI-1, STAT-6, CK-AE1/ AE3, TTF1, and YAP-1. Descriptive statistical was used. Results: 4 patients were studied: Two women, 23 and 25 years old, diagnosed as TSC patients at 10 and 12 years of age, and two men with solitary SEGA (18 and 46 years old). Tumors were positive to GFAP, NF, nestin, and TTF1. Cytoplasmic STAT6 and CK stains was observed in all patients. 2/4 cases showed YAP-1 nuclear expression. TSC patients retained INI-1 nuclear expression, while solitary SEGAs lost it. Conclusions: SEGA is a glioneuronal tumor that expresses markers of neuroepithelial stem cells and cytokeratins. Its diagnosis must be supported with a minimal IHC panel: GFAP, neurofilaments, synaptophysin, nestin and TTF1. Morphological differences were observed between the TSC related and solitary SEGAs and in INI1 expression. Nuclear expression of YAP-1 in 2/4 tumors, opens the possibility of research for combined use of YAP and mTOR regulators in the management of SEGA. [ABSTRACT FROM AUTHOR]

In some way, neurodegenerative diseases are all proteinopathies. Although the main risk factor is aging, both genetics and environmental factors (trauma, pesticides, herbicides) are involved through epigenetic mechanisms in the development of proteinopathies. A range of possibilities for their presentation occurs, from absolute genetic risk (Huntington's disease) until the almost exclusive environmental factor (pugilistic dementia). Similarly, the complex range of symptoms and signs of these diseases contribute to flawed diagnosis (Parkinson's disease and supranuclear progressive paralysis, for example). Several authors propose that diseases thought until now to be different, may be exactly the same (Parkinson's disease and Lewy Body Dementia). Their pathophysiology is similar, starting from functional or structural proteins that become misfolded, dysfunctional and insoluble. These proteins become toxic, leading to neuronal death with the consequent inflammation in cortical, subcortical, basal ganglia, brain stem and spinal cord nuclei, and even peripheral nervous system structures. This progression could explain the manifestations that may result in the characteristic semiology of each neurodegenerative disease. [ABSTRACT FROM AUTHOR]