1. Departments of Dermatology
2. Pathology, Leiden University Medical Center, Leiden, the Netherlands
3. Department of Dermatology, Vrije Universiteit Medical Center, Amsterdam, the Netherlands
4. Department of Dermatology, Academic Medical Center, Amsterdam, the Netherlands
5. Department of Dermatology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
6. Laboratorium Pathologie Oost‐Nederland, Enschede, the Netherlands