Angiolymphoid Hyperplasia with Eosinophilia and Radial Artery Pseudoaneurysm

A case of angiolymphoid hyperplasia with eosinophilia arising from the radial artery is presented. Histologically, there was proliferation of atypical endothelial cells forming vascular spaces and solid cords, with a background infiltrate of inflammatory cells and prominent tissue eosinophilia. Immunohistochemical studies demonstrated vimentin and Factor VIII-related antigen in the endothelial cells. The lymphoid infiltrate was polyclonal. The authors discuss the probable nature of this process, which typically occurs in the dermis and subcutaneous tissue of the head and neck and is known by a variety of different names, reflecting disagreement regarding pathogenesis. This case draws attention to the fact that it can arise not only within the dermis and subcutaneous tissue of the head and neck, but also from major peripheral arteries. Angiolymphoid hyperplasia with eosinophilia should be considered promptly in the doubtful case of a pulsatile mass arising from peripheral arteries as it may lead to an earlier diagnosis and timely treatment with lower morbidity.