Hemangiopericytoma-Like Tumour

 

Epidemiology:

    •  

 

Common sites:

    • paranasal sinuses
    • nasal cavity

 

Gross features:

    • clinically resembles allergic polyp

 

Histologic features:

    • vascular
    • highly cellular
    • little atypia, necrosis, or mitotic activity

 

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Vimentin (strong) 

 

 

Actin (focal)

 

 

 

Molecular features:

    •  

 

Other features:

    • cells are closely related to glomus cells
    • EM:
      • Basal lamina material enwrapping individual cells
      • Tapered cytoplasmic extensions
      • Orderly bundles of filaments