- Common benign tumor arising from vascular smooth muscle
- Most common on the limbs of adults
- Female predominance
- May be painful
- Round, encapsulated mass in the deep dermis or subcutaneous fat
- Comprised of fascicles of monotonous smooth muscle cells with numerous interspersed small blood vessels with walls of varying thickness
- Occasional cells with enlarged, hyperchromatic nuclei may be seen: not indicative of malignancy, but probably a degenerative change.
- Common changes include: hyaline, myxoid and dystrophic calcification.
- If foci of mature adipose tissue are present, may be termed angiomyolipoma or angiolipoleiomyoma.
- May rarely show epithelioid cell change or palisading mimicking Verocay bodies.
- Postitive for smooth muscle markers: SMA, calponin, desmin, h-caldesmon