Retiform Hemangioendothelioma

**Semantic type:** Neoplastic Process

**Definition:** A rare, intermediate, locally aggressive and rarely metastasizing blood vessel neoplasm of the skin and subcutaneous tissue that usually affects the distal extremities, most often the leg. It manifests as a slow-growing red/bluish nodule or plaque and is characterized by the presence of hobnail endothelial cells and formation of arborizing vascular channels.

**Synonyms:** - Hobnail Hemangioendothelioma - RHE