A Case Report of the Intravascular Fasciitis of a Neck Vein Mimicking Intravascular Tumorous Conditions.

Intravascular fasciitis is a rare variant of nodular fasciitis, which can be easily misdiagnosed as a tumorous condition. We had a patient with an intravenous mass of a neck vein, and surgical excision was successful. Although all preoperative imaging studies and intraoperative pathologic reports suggested certain tumorous conditions as differential diagnosis results, the final diagnosis confirmed that it was an intravascular fasciitis based on its fibromixoid tissues with the proliferation of spindle cells and positive immunohistochemical staining for smooth muscle actin. Unless a physician has an insight of the disease or a suspicion to initiate running differential markers, it may be confused with other intravascular lesions and cause unnecessary radical surgery. Here we report our experience with a patient having this rare vascular disease.