C, Epithelioid angiosarcoma demonstrates focal vasoformative
In grade-2 lesions, the tumour is still easily recognizable as vasoformative
and the endothelial cells have moderate atypia.
Atypical vascular proliferations, which have been described under various nomenclature designations, occur in areas of prior radiation, are often seen in association with angiosarcoma, and in some cases may be difficult to distinguish from vasoformative
(angiogenic) tumors of the soft tissues of the head and neck account for fewer than 0.
Splenic hamartoma, otherwise known as splenoma or splenadenoma, is another rare vasoformative
lesion of the spleen.
They are benign vascular malformations that originate in mesodermal nests of vasoformative
This rudimentary vasoformative
architecture is clearly demonstrated with reticulin staining (Figure 2).
Since epithelioid hemangioendotheliomas and angiosarcomas may express cytokeratins, even if a vasoformative
tumor is keratin positive, the tumor should be stained with vascular markers.
The tumor typically shows features of angiosarcoma including vasoformative
architecture with hobnailed appearance (Figure 3) and it has infiltrative margins.
This case also showed a transition to a higher-grade tumor, which was vaguely vasoformative
and mitotically active, suggesting progression to an EA.
The cytologic appearance can be epithelioid, spindled, or pleomorphic (Figure 6, A through C), while the architecture can be vasoformative
, sievelike, kaposiform, or solid (Figure 7, A through D).
They suggest that in VPTR, the significant proliferative activity is astrocytic and that, presumably, the vascular component is secondary to the release of vasoformative
factors by the glial cells.