It is the most common benign tumor of the liver. It is composed of dilated vascular spaces lined by endothelial cells. When a spindle cell lesion is observed on FNA, it is most likely a hemangioma. In some cases only blood or benign hepatocytes are observed.
Cytologic diagnostic features
- Three-dimensional arcades of bland elongated spindle cells
- Compact, dense coils of spindle cells
- Rare isolated spindle cells
- Vascular channels lined by endothelial cells (cell block sections)