Fig. 3

a–c Micrographs of the image-directed brain biopsy. Micrographs of low (a), intermediate (b), and high (c) power illustrating images of the brain biopsy stained with anti-calretinin antibody. a Low power overview of an arterial vessel illustrating replacement of the normal lining endothelium with metastatic myxoma cells stained for calretinin and direct extension of the tumor cells through the vessel wall and into surrounding brain parenchyma. The box denotes the microscopic field presented in panel b. b Intermediate power image illustrating the replacement of normal endothelium with anti-calretinin-staining atrial myxoma cells and invasion of the vessel wall and brain parenchyma by the myxoma cells. c High power image illustrating individual calretinin-positive atrial myxoma cells which have replaced the normal vessel endothelium and the subendothelium (yellow arrowheads) with myxoid matrix and invasion by individual tumor cells through the media of the vessel wall and into adjacent brain parenchyma (yellow arrows). The dashed lines denote the internal and external elastic lamina marking the vascular smooth muscle and extracellular matrix the comprises the media of the vessel