Prominent EMA 'dots' in tumour-induced Bergmann gliosis

作者：Gelpi Ellen^*; Bombi Josep A; Martinez Saez Elena; Caral Luis; Ribalta Teresa

来源：Histopathology, 2014, 64(3): 445-452.

DOI：10.1111/his.12260

• Bergmann glia
• dots
• EMA
• immunohistochemistry
• leptomeningeal sarcomatosis

AimsTo describe an unusual pattern of epithelial membrane antigen (EMA) immunoreactivity in highly proliferative human Bergmann glia.
Methods and resultsAn immunohistochemical study was performed of postmortem cerebellar tissue from 18 adult patients with cerebellar damage of various aetiologies and 15 biopsies of diverse adult and paediatric cerebellar tumours. We observed marked proliferation of Bergmann glia with unusual prominent dot-like cytoplasmic EMA immunoreactivity in a case with extensive leptomeningeal sarcomatosis. Similar staining was not observed in association with other types of cerebellar pathology, except for other neoplastic conditions, such as leptomeningeal carcinomatosis, adult medulloblastoma, and pilocytic astrocytoma in children. At an ultrastructural level, the index case showed prominent endoplasmic reticulum with some intermediate filaments and lipofuscin granules, but no structures related to cilia or microvilli were observed.
ConclusionsWe consider that prominent EMA dots in Bergmann glia might represent excessive activation induced by an overlying leptomeningeal tumour that stimulates the expression of early developmental antigens. This observation suggests modulation of the glial phenotype when exposed to a neoplastic microenvironment that, in turn, might influence the regenerative potential of Bergmann glia.

• 出版日期2014-2