Granulomatous mycosis fungoides presenting as sarcoidosis

This report describes the case of a woman who developed cutaneous granulomatous infiltration during childhood that was initially considered to be sarcoidosis and, after 27 years of evolution, was determined to be caused by granulomatous mycosis fungoides transforming to Ki-1-positive anaplastic large-cell lymphoma of T-cell type. We discuss the differential diagnosis, especially granulomatous slack skin and the interest of immunohistochemical and genotypic studies in this case.