Pathologic appraisal of the thymus gland in acquired immunodeficiency syndrome in children. A study of four cases and a review of the literature.

We studied the entire thymus gland by step-serial sections in four fatal cases of acquired immunodeficiency syndrome (AIDS) in children. The location, configuration, and blood vessels of the thymus gland were normal. The weight was reduced. There was severe depletion of both lymphocytes and Hassall's corpuscles. Because of the normal location, configuration, and blood vessels and the seemingly less severe lymphocytic depletion than is seen in congenital immunodeficiency syndromes and because of the clinical and epidemiologic features, we concluded that this syndrome in children represents AIDS. We postulated that the epithelial cells of the Hassall's corpuscles may be the primary site of thymic injury in AIDS.