Ignorance in infectious diseases: the case of AIDS, Kaposi sarcoma, and lymphology.

From the perspective of The University of Arizona's innovative Curriculum on Medical (and Other) Ignorance focusing on "what we know we don't know, don't know we don't know, and think we know but don't," the shifting terrain of information-knowledge-ignorance of AIDS (a disorder involving, to various incompletely understood degrees, the four components of the lymphatic system-lymph, lymphatics, lymphocytes, and lymph nodes) and Kaposi sarcoma (a lymphedemogenic lesion thought to arise from trans-differentiated lymphatic endothelium) is surveyed by pinpointing some key unanswered questions that have been raised over the course of the epidemic and pointedly in past International Congresses of Lymphology. These questions are placed in the context of general ignorance about infectious diseases and the relationship of "germ" to "terrain" through the "blood-tissue-lymph loop." A framework is suggested for an "ignorance agenda" encompassing basic biology, clinical management, and societal issues.