Autopsy, histology and cytology have been and histology and cytology still are the main diagnostic tools in surgical pathology. During the last two decades molecular biology gradually has extended the diagnostic armamentarium. In tumor pathology molecular biology techniques are used to diagnose and subclassify tumors, predict response to therapies and identify therapeutic targets. Molecular pathology has evolved into a novel focus of clinical pathology and transforms the historically morphology based discipline. Traditional pathology and molecular pathology combine and guide tumor therapy.