Abstract
Distribution of Langerhans cells in thymic tissues and thymomas were examined by immunohistochemical analysis, using anti-S-100 antibody. Langerhans cells were demonstrated in 18 of 28 (64.3%) thymic tissues and in 31 of 37 (83.3%) thymomas. In thymic tissues, Langerhans cells were present mostly in the medulla. In thymomas, they were equally numerous in the cortical, medullary, and mixed types. In both thymic tissues and thymomas, Langerhans cells were more numerous in patients with myasthenia gravis (MG) than in those without, but the difference was not significant. Langerhans cells were more common in noninvasive than in invasive thymomas, but the difference was not significant.
