ABSTRACT
Neoplasms, or new growths, represent a spectrum of lesions ranging from benign to malignant in their behaviour. It is traditional for textbooks to provide a definition of neoplasia along the lines of Willis, and then proceed to list the differences between benign and malignant neoplasms. The classification of cancer is related to the concept of the body being formed of different types of tissue. The various tissues of the body have specific functions and specific structures. Columnar epithelium lines the gastrointestinal tract as well as the lung. The gut serves to absorb nutrients but also secretes mucus and digestive enzymes. Tissues that secrete are described as glandular and a simple gland is shaped like a microscopic flask or test tube and is lined by columnar or cuboidal epithelium. Carcinomas of ectodermal or endodermal origin may rarely contain sarcomatous-appearing elements and have been described as carcinosarcomas.
