The concept of malignant tumors, malignant tumors are named more complex, derived from epithelial cancer is called carcinoma, malignant tumor derived from mesenchymal tissue called sarcoma. Tightly packed epithelial cells, the distribution of organs in the body surface and inner surface, according to the form of epithelial cells can be divided into squamous epithelium, glandular epithelium and transitional epithelium, etc.; mesenchymal cells arranged in loose, located inside and outside between the epithelium, including fiber, fat, muscle, blood vessels, bone and bone level. If the human body compared to a bamboo, the bamboo as the epithelium, the outer two surfaces, like the bamboo leaf between the mezzanine. The outer surface of human skin, the inner surface of the mucous membrane of the gastrointestinal tract and bronchial malignant lung cancer known as time division to skin cancer, stomach cancer, colon cancer and lung cancer, such as with different epithelial types are called squamous cell carcinoma, rectal papillae like cancer, etc.; mesenchymal tissue such as fat, blood vessels and bone cancer occurs when assigned as liposarcoma, angiosarcoma and osteosarcoma.
The concept of malignant tumors, blood and lymphoid tissue also belong to leap when the organization, but malignant lung cancer, tumor cells often divided'm no mass formation, known as leukemia (commonly known as blood cancer); sometimes together tumor cells, known as malignant lymphoma .
The concept of malignant tumor have cancer and sarcoma within the same two subjects into yarn, called carcinosarcoma.
Derived from embryonic tissue, most malignant tumors such as neuroblastoma, Wilms tumor, retinoblastoma, etc.; a small number of benign tumors, such as fatty tumor, chondroblastoma and so on. From multiple (mesoderm) tissue tumor called teratoma, Hodgkin's disease (Hodgkin disease), Ewing sarcoma (Ewing sarcoma) and so on.