1. Division of Anatomic Pathology and Histology, ‘A. Gemelli’ School of Medicine, Catholic University of Sacred Heart, Rome, Italy
2. Division of Anatomic Pathology, University of Pennsylvania Medical Center, 3400 Spruce Street, 6 Founders Pavilion, Philadelphia, PA 19104-4283; Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA (USA)