In 1906, Alzheimer presented the first case of the disease which was later named Alzheimer's disease by Kraeplin. While the publication on this case in 1907 is only a relatively short communication, Alzheimer published a very comprehensive paper in 1911 in which he discussed the concept of the disease in detail. This publication focusses on the report of a second patient suffering from Alzheimer's disease, the case of Johann F. The detection of neurohistopathological sections from this patient found among archives at the Institute of Neuropathology of the University of Munich enabled us to reinvestigate this case using modern methods. Neurohistopathologically, the case of Johann F. is "plaque-only" Alzheimer's disease. There is a controversy in the modern literature as to whether these "plaque-only" cases belong to the modern concept of Alzheimer's disease. A careful analysis of all pros and contras in the literature led to the conclusion that plaque-only cases are also an integrative part of the modern Alzheimer disease concept.