Lever's histopathology of the skin / editor in chief, David E. Elder, MB, CHB, FRCPA, Professor of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania ; associate editors, Rosalie Elenitsas, MD, Professor of Dermatology, Director of Dermatopathology, Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, Misha Rosenbach, MD, Assistant Professor of Dermatology & Internal Medicine, Associate Program Director, Dermatology Residency, Director, Dermatology Inpatient Consult Service, Director, Cutaneous Sarcoidosis Clinic, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, George F. Murphy, MD, Professor of Pathology, Harvard Medical School, Director, Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, Adam I. Rubin, MD, Assistant Professor of Dermatology, Hospital of the University of Pennsylvania, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, Xiaowei Xu, MD, PhD, Associate Professor, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.