Localized mycosis fungoides with prominent epidermotropism: Woringer-Kolopp disease.

A patient had a single, large, sharply demarcated lesion on one leg. Under the mistaken diagnosis of malignant melanoma in situ, the lesion was excised and the area grafted in 1956. There has been no recurrence in the past 20 years. Histologic reevaluation led to a diagnosis of mycosis fungoides with pronounced epidermotropism of the cellular infiltrate. This case has close clinical and histologic resemblance with three cases published in Europe and regarded as a special form of reticulosis as first described by Woringer and Kolopp. Mycosis fungoides with marked epidermotropism is not always a benign localized disease but may be widespread and lead to death.