Thumbnail of A. Scanning electron microscopy shows the presence of leukocytes and red blood cells on the tip of the ventriculo-peritoneal mass, within which coccoid cells can be visualized. The enclosing matrix material has condensed by dehydration, but the outline of the 4- to 6-µm coccoid cells (arrow), similar to those of C. immitis, can be resolved within the mass (x4,000). B. Scanning electron microscopy of the surface of the ventriculo-peritoneal shunt, showing complete colonization of the surface by a matrix-enclosed biofilm formed by the cells of C. immitis. Within the dehydration-condensed matrix of this biofilm, a hyphal element (arrow) and coccoid cells (4-6 µm) of the pathogen can be discerned (x5,000).