1. From the Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands; the Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands; the Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands; Department of Pathology, University of Groningen, Groningen, the Netherlands; Department of Pathology, Vrije Universiteit Medical Center, Amsterdam, Netherlands; and the Department of Dermatology, University Hospital Gent, Gent, Belgium.