NCIt definition : An intermediate, rarely metastasizing blood vessel neoplasm that more frequently affects
young adult males and usually arises in the lower limbs. In approximately half of
the affected patients the tumor is painful and in two-thirds of the patients the tumor
is multifocal. Morphologically it is characterized by the presence of sheets and fascicles
of spindle cells with abundant eosinophilic cytoplasm and vesicular nuclei. Cytologic
atypia is usually mild. Approximately 60% of the patients develop local recurrences
or additional tumors in the same anatomic region.;