Intravascular papillary endothelial hyperplasia (also known as "Masson's hemangio-endotheliome vegetant intravasculaire," "Masson's lesion," "Masson's pseudoangiosarcoma," "Masson's tumor," and "Papillary endothelial hyperplasia") may mimic angiosarcoma, with lesions that are red or purplish 5-mm to 5-cm papules and deep nodules on the head, neck, or upper extremities.