The PI3K/Akt pathway is activated in both angiosarcoma of bone and soft tissue, however, with a different cause; PTEN expression is decreased in angiosarcoma of bone, whereas angiosarcomas of soft tissue show overexpression of KIT.
Activation was not related to intragenic deletion of phosphatase and tensin homolog (PTEN), an aberration that is frequent in LMS and UPS but absent in angiosarcomas.
These findings indicate that analysis of PTEN gene mutations may be useful for characterization of the molecular event in hepatic angiosarcoma and cancer predisposition.