Basal cell carcinomas arising over arteriovenous malformations: some speculations on the theme.

The modulating effects of mesoderm on ectoderm during the embryonic period have been well documented. Some cutaneous conditions such as dermatofibroma with basaloid proliferation are examples of such a relationship. Seven cases of basal cell carcinoma (BCC) developing in port-wine stains and one case developing over an arteriovenous (AV) malformation have been reported. We report 3 elderly patients with BCC developing over AV malformations of the lower extremities. The association between BCC and AV malformation range from a chance association to a complex interaction between mesenchyme and epithelium, in which mesenchyme induces and modulates epithelial growth through the elaboration of specific growth factors (GF).