Fig. 2

Representative histologic findings of EHE, AS, KS and ES. a EHE showed bland morphology that resembled PHE cases and consisted of fascicular proliferation of spindle-shaped cells that occasionally had intracytoplasmic lumina, with the appearance of primitive vessels. b AS was composed of solid and partly gland-like proliferation of spindle and/or epithelioid cells showing severe nuclear atypia and frequent mitotic figures. This case showed prominent epithelioid morphology and was diagnosed as epithelioid AS. c KS exhibited multilobulated vascular lesions that consisted of fascicular proliferation of endothelial spindle cells focally forming a vascular channel. d ES consisted of fascicular and solid proliferation of spindle-shaped and epithelioid cells with oval nuclei with moderate nuclear atypia