I Fernández-Vega1, J Santos-Juanes2, M F Fresno-Forcelledo2. 1. Service of Anatomic Pathology, Hospital Universitario de Araba, Vitoria, Spain. ivan_fernandez_vega@hotmail.com. 2. Service of Anatomic Pathology, Hospital Universitario Central de Asturias, Oviedo, Spain.