SCANNING ELECTRON MICROSCOPY OF NEOPLASMS REMOVED AT SURGERYSURFACE TOPOGRAPHY AND COMPARISON OF MENINGIOMAcomma; COLLOID CYSTcomma; EPENDYMOMAcomma; PITUITARY ADENOMAcomma; SCHWANNOMA AND ASTROCYTOMA

摘要

Twenty-one neuroectodermal tumors were examined and compared using scanning electron microscopy (SEM) monitored by light (LM) and transmission electron microscopy (TEM). A simplified procedure resulted in 4 to 8 hour total SEM processing time and revealed more surface features than cryofracturing. Examined with SEM, transitional meningiomas displayed distinctive whorls of flat cells with short, broad, tapering processes. Their surface ridges and intercellular connections probably reflect junctional complexes. Colloid cysts contained ciliated and sparsely ciliated or non-ciliated cells in a uniform mixture; the latter cells on TEM were found to have a surface coat of fine, oriented filaments. Long cilia of varied diameter and of an internal structure resembling sensory cilia were combined with other features indicating similarities between olfactory and colloid cyst epithelium. Ependymomas possessed spherical cells with numerous microvilli. In some foci long, cylindrical, smooth fibrils extended from these cells and branched frequently. Their surface features differed from nonfibrillar, polyhedral pituitary adenoma cells. Schwannomas displayed a rough, beaded surface on cells and fibrils associated with their basement membrane envelopes. Their fibrils were straighter, less rounded and less frequently branched than glial fibrils. Fibrils of pilocytic astrocytomas were smooth, cylindrical, and serpentine. They branched frequently and at wide angles. Their focal expansions were associated with Rosenthal fibers. SEM demonstrated the complex ramifications of neuroectodermal fibrils in greater depth than did routine TEM and with more resolution than LM. This study highlights examples in