A solid circumscribed, rounded lesion composed of spindle cells set within a fibrous stroma. The spindle cells display mildly irregular nuclei with inconspicuous nucleoli and a scant amount of cytoplasm. Mitotic activity is minimal and necrosis is not identified. There is no significant perivascular hyalinisation and a patchy mild perivascular lymphocytic infiltrate is present. Scattered mast cells are also seen.
20x H&E: well-circumscribed, solid lesion.
40x H&E: haphazard intersecting moderately cellular fascicles of spindle cells with scattered blood vessels.
200x H&E: perivascular chronic inflammatory cells.
200x H&E: cytologically bland nuclei with inconspicuous mitotic activity.
40x CD31: highlights vessels within lesion.
40x C-kit: highlights scattered mast cells.
100x ER: diffusely positive.