Intravascular fasciitis: report of an intraoral case and review of the literature.

Intravascular fasciitis (IF) is an unusual variant of nodular fasciitis. It is characterized by intraluminal, intramural, and extramural involvement of small to large arteries or veins. Only three cases involving the oral cavity have been reported previously in the literature. Here we present an additional case of oral IF arising in the submucosa of the upper lip of a 20-year old female. Microscopic examination showed a well-circumscribed, nodular proliferation of spindle cells arranged in intersecting fascicles. Occasional multinucleated giants cells also were noted. The tumor was present within the lumen of an intermediate-sized artery and extended into adjacent smaller vessels, thereby creating a multinodular appearance. Extramural extension into the surrounding connective tissue also was observed. Among the 31 cases of IF reported thus far (including the present case), the majority (n = 23) arose in individuals in the 1st through 3rd decades, with a 1.4:1 male:female ratio. The most common sites of involvement were the head and neck (n = 11) and upper extremity (n = 11), followed by the lower extremity (n = 6) and trunk (n = 3). Conservative excision is standard treatment, although local recurrence has been reported in three cases. It is important for the pathologist to be aware of this lesion in order to avoid misdiagnosis as a sarcoma with angioinvasion.