Pseudovascular adenoid squamous-cell carcinoma of the oral cavity--a report of two cases.

Informed consent was obtained for the publication of the patients' details in this report. Two cases of pseudovascular adenoid squamous-cell carcinoma (SCC) in the oral cavity are described, which were characterised by acantholysis of the tumour cells, with formation of anastomosing spaces and channels mimicking an angiosarcoma. Both tumours contained foci of SCC suggesting the correct diagnosis: in one patient conventional SCC, and in the other, a spindle-cell carcinoma. The pathogenesis of pseudovascular adenoid SCC is unknown. Our cases were characterised by loss of immunohistochemical expression of E-cadherin, one of the major adhesion molecules of epithelial cells. Pseudovascular adenoid SCC is suggested to be pathogenetically related to the loss of E-cadherin expression, leading to the loss of tumour cell-cell adhesion.