Since the Rye classification of Hodgkin's disease, many lesions which resemble Hodgkin's disease microscopically have been described. The histological features of Hodgkin's disease, including the BNLI subclassification of nodular sclerosis, and the lesions which resemble Hodgkin's disease microscopically such as reactive lymph node hyperplasias, some non-Hodgkin's B- and T-cell lymphomas are reviewed. Recent reclassifications of lymphomas originally diagnosed as Hodgkin's disease have indicated that the disease was overdiagnosed, before the description of these lesions and before the development of monoclonal antibodies.