Table 1 Similarities and differences between paranasal sinus angiosarcoma and other diseases

Reticulohistocytoma

• Infiltrate dermis

• CD31(+) Vimentin (+)

Human Melanoma Black-45(-) [36]

• Angiosarcomas: CD34 (+), Keratin (+), S-100 (-), Lysozyme (-), CD68 (-)

• Angiosarcomas often invade contiguous bone, soft tissues, and cartilage, as seen on a CT scan

• Angiosarcomas have haemorrhagic infiltration [37]

Intravascular papillary endothelial hyperplasia

• Predominant endothelial cell hypertrophy and formation of multiple papillae

• Bone erosion on CT scan

• CD31(+) CD34(+) Vimentin (+) [38]

• Angiosarcomas are invasive and rarely intravascular

• Angiosarcomas have a lot of necrotic and solid areas

• Angiosarcomas have pleomorphic cellularity and abundant mitotic morphology [38,39,40]

Epithelioid sarcoma

• Pleomorphism, spindle cells

• cutaneous lesions

• CD34(+)

ETS-related gene (+) [41, 42]

• Angiosarcomas express CD31, and no loss of INI/SMARCB [1]

• The pleomorphism of epithelioid sarcoma is usually mild to moderate [43]

melanoma

• Erythrophagocytosis

• Spindled, epithelioid, or plasmacytoid

• Large and prominent nucleoli [43]

• Cytoplasmic hemosiderin pigment

• Angiosarcomas express vascular markers and are negative for S100, Sox10, Melan-An, Human Melanoma Black-45 [43]