Foamy cell angiosarcoma: a rare and deceptively bland variant of cutaneous angiosarcoma.

Cutaneous angiosarcoma can sometimes mimic other benign and malignant lesions, thereby presenting a difficult differential diagnosis. In the two cases of cutaneous angiosarcoma presented herein, extensive foamy cell alteration of tumor cells resembled a reactive xanthogranulomatous process. Foamy cell angiosarcoma is an unusual and deceptively benign morphologic variant of cutaneous angiosarcoma. Critical features for diagnosis include the presence of a deep, permeative, sometimes 'scaffolding' growth pattern and subtle areas of vascular formation.