[Intravascular papillary endothelial hyperplasia: multiple lesions appearing in the course of treatment with interferon beta].

Introduction: Intravascular papillary endothelial hyperplasia is a benign and rare vascular lesion. We report a case of multiple vascular lesions of the hand following 3 months treatment with beta-interferon injections for multiple sclerosis.

Observation: A 50 year-old man had multiple vascular nodules of the hands. He was treated with beta interferon injections for multiple sclerosis for 3 months. Histology showed typical changes of intravascular papillary endothelial hyperplasia: papillary endothelial proliferation in a dilated cavity associated with thrombosis.

Discussion: Intravascular papillary endothelial hyperplasia is a benign and rare vascular lesion usually presenting as a simple nodule. It may be painful. Diagnosis is histologic, characterized by papillary endothelial proliferation associated with a thrombus within a vessel. It may be confused with hemangiosarcoma. Treatment is surgical and recurrence after treatment is rare. Intravascular papillary endothelial hyperplasia is generally considered as an unusual form of thrombus organization. Intravascular papillary endothelial hyperplasia is divided into two groups: a pure form occurring within a dilated vessel and a mixed form appearing in benign vascular lesions. The originality of this case is the rarity and the multiplicity of the lesions. The possible pathogenesis of interferon-induced cutaneous vascular lesions is discussed.