This video gives a brief introduction to the pathology of sebaceous glands, a comparison between normal and abnormal drainage from duct together with histopathological specimen consideration of normal and abnormal lineages. TIMELINE: 0:03 Introduction 0:25 Hairs on the scalp 1:40 Abnormal and normal; drainage from duct 2:43 Glands related to pathology 4:08 Diseases birthmarks 5:13 Histopathological consideration of nevus 7:39 End