VIMENTIN FILAMENT DESMOSOME CYTOSKELETON OF DIVERSE TYPES OF HUMAN MENINGIOMAS - A DISTINCTIVE DIAGNOSTIC FEATURE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 51  (5) , 584-591
Abstract
Ten human meningiomas of different histologic subtypes (endotheliomatous, transitional, fibroblastic and angioblastic) were examined for the expression of intermediate-sized filaments (IF) and desmosomal plaque proteins (desmoplakins I and II), using immunofluorescence and immunoelectron microscopy. All meningiomas gave a strong positive reaction for vimentin as well as for desmoplakins. IF of the cytokertain type, desmin IF, and glial filaments were not detected in any of these tumors. The exclusive expression of vimentin in these tumors was confirmed by 2-dimensional gel electrophoresis and immunoblot analysis of cytoskeletal proteins obtained after microdissection of well-defined tumor areas. Ultrastructural immunolocalizations showed that, in the various tumors, vimentin IF were attached to the desmosomal plaques. With respect to the markers examined, all of the diverse types of meningiomas reacted like their putative nonneoplastic counterparts, i.e., arachnoidal cells. The different histologic subtypes of meningiomas evidently are derived from cells of the arachnoidal layer. The exclusive expression of vimentin-type IF in combination with desmoplakins is very unusual and so far seems unique to arachnoidal and meningioma cells. This unusual combination, i.e., vimentin IF and desmoplakin plaques, is considered to be a diagnostic feature for meningiomas, and it is proposed that the cytoskeletal property be used in differential diagnosis of intracranial tumors.