Abstract
In this manuscript, we summarize the main features of angiomyolipoma highlighting the recognition of epithelioid angiomyolipoma and the discovery of immunohistochemical expression of HMB45 in a group of tumors that now are referred to as as PEComas. In this scenario, Dr. Rosai believed in our intuition, demonstrating his intellectual honesty and motivated us with his experience ("when a tumor seems malignant it is malignant") and enthusiasm for the new entities ("in Verona, you use HMB45 instead of H&E"). He really pushed the improvement of the knowledge in this field.