In this historical review I will synopsize the original articles by Lloyd W. Ketron and M.H. Goodman who described Ketron-Goodman disease, by Frederic Woringer and Pierre Kolopp who described Woringer-Kolopp disease, and by Otto Braun-Falco and colleagues who described pagetoid reticulosis. In their publications, each of these authors reported on one patient. I will review the clinical picture of the three patients, their histopathology, and the pathogenesis of each disease as suggested by the above authors. Then the views of others that have written on the subject recently will be reviewed particularly as to their conception of the diseases. Publications that describe the histopathology of the patch (early) stage of mycosis fungoides will be redacted to compare it to the histopathology of Ketron-Goodman disease, Woringer-Kolopp disease, and pagetoid reticulosis. I will discuss whether any or all of them are diseases sui generis, whether they are one, two, or three entities, or whether any or all are but forms of mycosis fungoides.