Ang-2 but not Ang-1 expression in perivascular soft tissue tumors.

Perivascular soft tissue tumors are relatively uncommon neoplasms of unclear line of differentiation, although most are presumed to originate from pericytes. Previously, we reported a shared immunophenotype across these related tumor types. Here, we extend these findings to examine the expression of the pericyte markers angiopoietin-1 and -2 (Ang-1 and -2) among perivascular soft tissue tumors. Results showed consistent Ang-2 but not Ang-1 expression across tumor types. In summary, the absence of Ang-1 expression distinguishes perivascular from vascular soft tissue tumors. Ang-2 expression is present across perivascular soft tissue tumors, with some variation between histologic subtypes.