title: Structure of psammoma bodies of a meningioma in scanning electron microscopy.
abstract: Psammoma bodies in a human transitional meningioma were studied by scanning electron microscopy (SEM) of deparaffinized tissue slices and sections. The bodies, visible as round structures by light microscopy, were confirmed in SEM to have a spherical rather than tubular three-dimensional structure. They were distinctly demarcated from a surrounding cup-like wall of cells. Under high magnification, the undulating surface of the bodies was found to be covered by interwoven fibers. In cross-section the bodies had a lamellar internal structure. The lamellae consisted of a network of concentric strands and fibers with associated bead-like material. The structure of psammoma bodies seen in SEM speaks in favor of their genesis by calcification of concentrically deposited fibrillar extracellular material.
mesh_terms: D000368:Aged; D001932:Brain Neoplasms / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008579:Meningioma / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning