Cutaneous angiolymphoid hyperplasia with high endothelial venules is characterized by endothelial expression of...

Two cases in which the presence of cutaneous lesions with a characteristic admixture of lymphoid hyperplasia and vascular proliferation lead to the diagnosis of so-called acral pseudolymphomatous angiokeratoma (APA) of children are reported. Owing to the prominence of its blood vessels, so striking as to be reminiscent of high endothelial venules (HEVs), APA was initially interpreted as a vascular lesion rather than a pseudolymphoma. This resemblance is further compounded by our finding that cutaneous lymphocyte antigen (CLA), an HEV marker, is also expressed in APA epithelioid blood vessels. Consequently, we believe that "cutaneous angiolymphoid hyperplasia with high endothelial venules" (ALH-HEV), which alludes to the dual nature of proliferating elements and the HEV-like phenotype of the vascular component, would be a better denomination for this entity. Additionally, we speculate that ALH-HEV lymphoid hyperplasia self-perpetuates through the transformation of dermal capillaries into HEVs, which would bind non-skin homing lymphocytes expressing L-selectin and promote their local recruitment and recirculation.