We report a case
of unusual hemangioblastoma in a middle-aged man with von Hippel-Lindau disease. Neuroimaging revealed multifocal gadolinium-enhancing masses were located within both sides of the cerebellar hemisphere. Histologically, only small areas showing the typical morphology of hemangioblastoma find more were recognized in masses. Most areas of masses were composed of cohesive epithelioid tumor cells with abundant cytoplasm and distinct boundaries. Epithelioid tumor cells were arranged around blood vessels, exhibiting perivascular anuclear zone structures like ependymoma. The epithelioid tumor cells were diffusely positive for vimentin, CD99, neuron-specific enolase, GFAP and focally positive for epithelial membrane antigen (EMA) and D2-40 in a dot-like pattern. Variable-sized lipid droplets and glycogen particles were noted in the cytoplasm of epithelioid tumor cells under an electron microscope. A diagnosis of epithelioid cellular hemangioblastoma with possible ependymal differentiation (WHO grade I) was made. To our knowledge, only a few cases of hemangioblastoma show epithelioid appearance or EMA immunoreactivity. The present case indicates that the stromal cells of hemangioblastoma might originate from primitive neuroectodermal cells,
and they have the capacity to show a distinctive sign of glial or ependymal differentiation. “
“D. J. Bonda, V. P. Bajić, B. Spremo-Potparevic, G. Casadesus, X. Zhu, M. A. Smith and H.-G. Lee (2010) Neuropathology and Applied Neurobiology36, 157–163 Cell cycle aberrations ABT-263 order and
neurodegeneration The cell cycle is a highly regulated and fundamental cellular process that involves complex feedback regulation of many proteins, and any compromise to its integrity elicits dire consequences for the cell. For example, in neurodegenerative diseases such as Alzheimer disease (AD), evidence for abnormal cell cycle re-entry precedes other hallmarks of disease and as such, implicates cell cycle aberrations in the aetiology of AD. The mechanism(s) for Molecular motor cell cycle re-entry in AD, however, remain unclear. Current theory suggests it to be part of a combination of early events that together elicit the degenerative pathology and cognitive phenotype consistent with the disease. We propose a ‘Two-Hit Hypothesis’ that highlights the concerted interaction between cell cycle alterations and oxidative stress that combine to produce neurodegeneration. Here, we review the evidence implicating cell cycle mechanisms in AD and how such changes, especially in combination with oxidative stress, would lead to a cascade of events leading to disease. Based on this concept, we propose new opportunities for disease treatment. “
“Meningeal hemangiopericytomas (HPCs) are aggressive dural-based tumors, for which no prognostic or predictive marker has been identified. Gross total resection is treatment of choice, but not easily achieved; hence, alkylating agents like temozolomide (TMZ) are now being tried.