A typical benign tumour is usually encapsulated within a membrane of a connective tissue. Microscopically, the benign mass has a homogenous appearance if it is derived from one type of tissue. An individual type of cells all appear alike. Degenerative and regressive changes are much less frequent than in malignant tumours, and the patterns of benign tumours are usually orderly. They do not metastasize .(Both benign tumours and malignant tumours are often referred to as neoplasms).