Low power: Pap Stain
Fragments of bland cells
Low power: Pap Stain
Bland endothelial cells
Medium power: Pap Stain
Fragments of blood vessels from a hemangioma
Medium power: Pap stain
Bland spindle cells with uniform spindled nuclei
Medium power: Pap stain
Fragment of spindle cells with uniform nuclei and moderate amount of pale cytoplasm
Cell block: H&E stain
Small fragment of blood vessels in a background of blood
Cell block: H&E stain
Vascular architecture better seen in cell block sections
Features
• Benign tumor resembling normal blood vessels
• Skin, subcutaneous tissue, other sites like liver
• Bloody specimen
• Low cellularity
• Often non-diagnostic on aspiration
• Cell clusters around lumens or vessels
• Bland spindle cells
• Cytoplasm pale and delicate to dense
• Bland uniform nuclei
• May have nuclear groove
• Inconspicuous nucleoli
• May have rare mitosis
• Hemosiderin may be present
• May have surrounding adipose tissue
• IHC: CD31, CD34 and factor VIII positive in endothelial cells