Lobulated; hypocellular spindle-stellate cells with zonation
Amphophilic cytoplasm
Ovoid, occasionally smudged, nuclei with minimal atypia; inconspicuous mitotic activity
Abundant collagenous stroma, with myxoid degeneration; extravasation of erythrocytes, organizing thrombin
Capillary-like vessels concentrated at periphery; larger vessels with hyalinized "leaky" walls