Intravascular Papillary Endothelial Hyperplasia

**Semantic type:** Disease or Syndrome

**Definition:** A reactive, well-circumscribed vascular lesion. It is characterized by the formation of thin papillae projecting within the lumen of blood vessels. The papillae are lined by plump endothelial cells. Blood clots are also present.

**Synonyms:** - Masson Hemangioma - Masson Lesion - Masson Pseudotumor - Masson Tumor - Masson lesion - Masson's Pseudosarcoma - Masson's Pseudotumor - Masson's Vegetant Hemangioma - Papillary Endothelial Hyperplasia