Low power: Pap stain
Modestly cellular smear with adipocytes and vascular structures
Medium power: Pap stain
Endothelial cells running through adipocytes
Medium power: Pap stain
Predominantly adipocytes and vascular structures
Medium power: Pap stain
Endothelial cells admixed with adipose tissue
High power: Pap stain
Endothelial cells admixed with adipose tissue
Features
Architecture
• Vascular tumor composed of mature adipose tissue and blood vessels
• Varying cellularity
Cellular features
• Adipose tissue with lipocytes
• Vascular tissue composed of endothelial cells
Background
• May have increased mast cells
• Mitoses and increased cellularity may indicate malignancy (D/D Kaposi sarcoma and angiosarcoma)
Ancillary studies
• Express CD31, CD34
Reference
Chhieng DC et al. Cancer. 1999 Dec 25;87(6):359-71.