Lymphocytic vasculitis in livedoid vasculopathy: A report of 137 cases

Background: Livedoid vasculopathy (LV) is characterized by fibrin deposition and thrombosis in the small vessels of the superficial dermis. It is widely recognized as an occlusive disease, which is primarily treated with anticoagulation therapy.Method: sWe retrospectively analyzed the clinical and histopathological characteristics of patients diagnosed with LV at a tertiary dermatology department to explore the characteristics of lymphocytic vasculitis in LV. The frequency of vasculitis and the types of vessels involved were examined based on the diameters and elastic fiber distribution of the involved vessels. In addition, the immunophenotypes of infiltrating lymphocytes were analyzed.Results: In a large retrospective series including 358 LV cases, we identified 137 (38.3%) cases of lymphocytic vasculitis. Among them, 48 cases involved medium-sized vessels, including arterioles and venules, whereas 89 cases involved only small vessels. In addition, 12 cases displayed a segmental distribution of vasculitis. The infiltrating lymphocytes were mainly T cells, with dominant cells stained positive for CD4.Conclusions: Lymphocytic vasculitis forms part of the histological spectrum of LV, affecting both medium-sized and small vessels. It is possible that the occlusion of small vessels may represent a phenomenon secondary to lymphocytic vasculitis.