AFX

MFH/UHPS

Clinical presentation

< 2cm, actinic damaged skin of head and neck, median age 69.

> 5cm, deep soft tissues of proximal extremities (most frequently lower), not associated with actinic damage, median age 60 y/o.

Location is tissue

Dermal based tumor,  can exhibit focal subcutaneous extension

Subcutaneous or fascial based tumor, can exhibit dermal extension. More often associated with lymphovascular invasion &  geographic necrosis

Immunohistochemical staining

CD99 (15- 100% ++/+++)

PC1 (79%-87% +++)

CD10 (92-100% +++)

CD74 (90% -)

CD99 (15-35% ++/+++)

N/A

CD10 (70% +++)

CD74 (90% +++)

Gene mutations

P53 gene mutation

H-ras and K-ras gene mutation in 2/8 cases studied

Recurrence

2-21%

16-39%

Metastases

<1%; 58% lymph nodes, 35% visceral organs

30-44%; 90% lungs