Factor VIII-related antigen (von Willibrand factor, vWF)

This antigen is exclusively synthesised by endothelial cells, where it is present within the Weibel-Palade bodies and by megakaryocytes.

Immunohistochemical expression

Positive staining is seen in endothelial cells, megakaryocytes, platelets and mast cells.

The sinusoidal endothelial cells of liver, spleen and lymph nodes show variable positivity.

Vascular tumours, but sensitivity is low, with staining of only 50% of benign vascular tumours and fewer malignant ones, especially in non or poorly vasoformative areas1.

Diagnostic utility

It is used to identify vascular tumours, but is limited by a low sensitivity. High grade angiosarcomas have only sparse Weibel-Palade bodies, giving immunoreactivity in only 10-15% of cases2. It is more useful in benign haemangioma variants and haemangioendotheliomas2.


1Nicholson, S. A., McDermott, M. B., DeYoung, B. R., Swanson, P. E. CD31 immunoreactivity in small round cell tumors. Appl Immunohistochem Molecul Morphol 2000;8:19-24.

2Diagnostic Immunohistochemistry edited by Professor D. J. Dabbs, page 71

This page last revised 21.12.2001.

©SMUHT/PW Bishop