Involvement of subcutaneous veins in lepromatous leprosy.

Venous involvement in 31 patients with lepromatous leprosy has been studied in biopsies from clinically involved and clinically normal subcutaneous veins from the forearm. Twenty-nine of these showed histological evidence of leprous phlebitis. The earliest lesion was intimal cell hyperplasia with the presence of acid-fast bacilli in small groups in the intimal cells. This gradually progressed to total occlusion of the vein by lepromatous exudate. The results indicate much greater involvement of veins and possibly other components of the vascular system in patients with lepromatous leprosy than is generally accepted. The importance of such involvement in the pathogenesis of leprosy is also discussed.