Circumscribed; variable cellularity
Spindle-epithelioid cells with haphazard pattern (the latter tends to concentrate around vessels)
Eosinophilic cytoplasm with delicate tapering processes
Ovoid-round nuclei with occasional bi- and multi-nucleation; inconspicuous mitotic activity
Oedematous stroma with abundant wavy collagen bundles and occasional mast cells; prominent small, ectatic thin-walled vessels
IHC: desmin
Circumscribed with thin fibrous pseudocapsule; variable cellularity
Spindle-epithelioid cells with haphazard pattern (the latter tends to concentrate around vessels)
Eosinophilic cytoplasm with delicate tapering processes
Ovoid-round nuclei with occasional bi- and multi-nucleation; inconspicuous mitotic activity
Oedematous stroma with coarse collagen bundles; prominent small, ectatic vessels with hyalinized walls
These tumours typically express desmin