Tumor (American English) or tumour (British English) originally means "swelling", and is sometimes still used with that meaning. Tumor meaning swelling is one of the five classical characteristics of inflammation. However, the term is now primarily used to denote abnormal growth of tissue. This growth can be either malignant or benign. It is similar in meaning to a neoplasm. American English (AmE) is the form of the English language used mostly in the United States of America. ... British English (BrE) is a term used to differentiate the form of the written English language in the United Kingdom from other forms of the English language. ... Inflammation is the first response of the immune system to infection or irritation and may be referred to as the innate cascade. ... Biological tissue is a substance made up of cells that perform a similar function. ... In medicine, malignant is a clinical term that is used to describe a clinical course that progresses rapidly to death. ... yeaaaaaaaa poopsicle ... Neoplasia (literally: new growth) is sudden and abnormal growth in a tissue or organ. ...

Tumor Types: Malignant vs. benign

Malignant tumors are called cancer. Cancer has the potential to invade and destroy neighboring tissues and create metastases. Benign tumors do not invade neighboring tissues and do not seed metastases, but may locally grow to great size. They usually do not return after surgical removal. When normal cells are damaged or old they undergo apoptosis; cancer cells, however, avoid apoptosis. ... Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ...

An epithelial tumor is considered malignant if it penetrates the basal lamina and is considered benign if it does not. The basal lamina (often erroneously called basement membrane) is a layer on which epithelium sits. ...

As people get older, they accumulate more mutations in their DNA. This means that the prevalence of tumors increases strongly with increasing age. It is also the case that the older a person with a tumor is, the higher the chances are that the tumor is malignant. For example, if a woman of 20 years old has a tumor in her breast it is very likely that the tumor is benign. However, if a woman of 70 has a tumor in her breast it is almost certain that it is malignant. The prevalence of a disease in a statistical population is defined as follows: Prevalence is useful because it is a measure of the commonality of disease. ...

Anaplasia is a term that refers to the histologic grade of a tumor. Anaplastic tumors are poorly differentiated, meaning that their cells look primitive and do not resemble normal cells. Having anaplasia in a tumor usually means that the tumor is malignant, although a malignant tumor need not be anaplastic. A thin section of lung tissue stained with hematoxylin and eosin. ... A grade may refer to many different concepts, including: in various contexts: Each item in a (generally ordered and finite) collection of symbols or designators used as a particular grade system to distinguish and rank corresponding groups, where distinct members or instances of each group are regarded as sufficiently similar... Cellular differentiation is a concept from developmental biology describing the process by which cells acquire a type. The morphology of a cell may change dramatically during differentiation, but the genetic material remains the same, with few exceptions. ... Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms, and are sometimes called the building blocks of life. ...

Tumor Types

Codes listed are ICD-O. The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ...

See also List_of_distinct_cell_types_in_the_adult_human_body In zootomy, epithelium is a tissue composed of a layer of cells. ... The squamous epithelium is epithelium consisting of one or more cell layers, the most superficial of which is composed of flat, scalelike or platelike cells. ... In medicine, squamous cell carcinoma is a form of cancer of the carcinoma type that may occur in many different organs, including the skin, the esophagus, the lungs, and the cervix. ... The basal cell layer is also called the Stratum Germinativum or Stratum Basale and is the innermost layer of the epidermis. ... Basal cell carcinoma (BCC) is the most common skin cancer in humans. ... In zootomy, epithelium is a tissue composed of a layer of cells. ... Adenoma refers to a collection of growths (-oma) of glandular origin. ... In medicine, carcinoma is any cancer that arises from epithelial cells. ... In humans, gastrin is a hormone that stimulates secretion of gastric acid by the stomach. ... X-Ray of the bile duct during a laprascopic cholecystectomy A bile duct is any of a number of long tube-like structures that carry bile. ... In zootomy, epithelium is a tissue composed of a layer of cells. ... Hepatocytes make up 60-80% of the cytoplasmic mass of the liver. ... Hepatocellular carcinoma (HCC, also called hepatoma or liver cancer) is a primary malignancy (cancer) of the liver. ... Human kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... Renal cell carcinoma, also known by the eponym Grawitz tumor, is the most common form of kidney cancer arising from the renal tubule. ... Renal cell carcinoma, also known by the eponym Grawitz tumor, is the most common form of kidney cancer arising from the renal tubule. ... Melanocytes are cells located in the bottom layer of the skins epidermis. ... A glomus tumor is a rare neoplasm usually found in the skin of the extremities. ... A mole or melanocytic naevus is a small spot of darkened pigment on the skin, which forms where there is a high concentration of melanin. ... Melanoma is a malignant tumour of melanocytes. ... In zootomy, fibrous connective tissue (FCT) is a type of connective tissue which has relatively high tensile strength, due to a relatively high concentration of collagenous fibers. ... Fibroma. ... Fibrosarcoma (fibroblastic sarcoma) is a malignant tumor derived from fibrous connective tissue and characterized by immature proliferating fibroblasts or undifferentiated anaplastic spindle cells. ... A myxoma is the most common primary tumor of the heart. ... Adipose tissue is an anatomical term for loose connective tissue composed of adipocytes. ... A lipoma is a benign tumor composed of fatty tissue. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Smooth muscle is a type of non-striated muscle, found within the walls of hollow organs; such as blood vessels, bladders, uteri. ... A leiomyoma (plural is leiomyomata) is a benign smooth muscle neoplasm that is not premalignant. ... A sarcoma is a cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. ... A top-down view of skeletal muscle Skeletal muscle is a type of striated muscle, attached to the skeleton. ... A rhabdomyoma is a benign tumor of muscle. ... A rhabdmyosarcoma is a form of cancer of the sarcoma subtype that shows differentiation or determination towards resembling skeletal muscle. ... Gametes (in Greek: γαμέτες) —also known as sex cells, germ cells, or spores—are the specialized cells that come together during fertilization (conception) in organisms that reproduce sexually. ... A teratoma is a type of tumor that derives from pluripotent germ cells. ... A teratoma is a type of tumor that derives from pluripotent germ cells. ... The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Hemangioma is a benign tumor, usually in the shape of a ball, but sometimes a flatter mat, formed by a collection of excess blood vessels in an area. ... Hemangiosarcoma is a rapidly growing, highly invasive variety of cancer. ... In mammals including humans, the lymphatic vessels (or lymphatics) are a network of thin tubes that branch, like blood vessels, into tissues throughout the body. ... Lymphangioma is a uncommon benign slow-growing congenital tumor derived of the lymphatic vessels. ... Grays illustration of a human femur, a typically recognized bone. ... An osteoma is a new piece of bone growing on another piece, typically the skull. ... Osteosarcoma is a common primary bone cancer. ... Cartilage is a type of dense connective tissue. ... Chondroma is a benign cartilaginous tumor, encapsulated, with a lobular growing pattern. ... A chondrosarcoma is a cancer of the cartilage. ... The meninges (singular meninx) are the system of membranes that contain the central nervous system. ... Meningiomas are tumors arising from the outer part of the arachnoid mater in the meninges of the brain or the spinal cord. ... A blood cell is any cell of any type normally found in blood. ... Wikipedia does not have an article with this exact name. ... Non-Hodgkins lymphoma is a type of cancer. ... Hodgkins disease is a type of lymphoma described by Thomas Hodgkin in 1832, and characterized by the presence of Reed-Sternberg cells. ... Red blood cells (erythrocytes) are present in the blood and help carry oxygen to the rest of the cells in the body Blood is a circulating tissue composed of fluid plasma and cells (red blood cells, white blood cells, platelets). ... Leukemia (leukaemia in Commonwealth English) are malignancies (cancers) of the blood or bone marrow characterized by an abnormal proliferation of white blood cells (leukocytes). ... Keratinizing epithelial cells Epidermal keratinocyte (differentiating epidermal cell) Epidermal basal cell (stem cell) Keratinocyte of fingernails and toenails Nail bed basal cell (stem cell) Medullary hair shaft cell Cortical hair shaft cell Cuticular hair shaft cell Cuticular hair root sheath cell Hair root sheath cell of Huxleys layer Hair...

Causes

Tumors are caused by mutations in DNA of cells. An accumulation of mutations is needed for a tumor to emerge. Mutations that activate oncogenes or repress tumor supressor genes can eventually lead to tumors. Cells have mechanisms that repair DNA and other mechanisms that cause the cell to destroy itself by apoptosis if DNA damage gets too severe. Mutations that repress the genes for these mechanisms can also eventually lead to cancer. A mutation in one oncogen or one tumor repressor gene is usually not enough for a tumor to occur. A combination of a number of mutations is necessary. In biology, mutations are permanent, sometimes transmissible (if the change is to a germ cell) changes to the genetic material (usually DNA or RNA) of a cell. ... Space-filling model of a section of DNA molecule Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions specifying the biological development of all cellular forms of life (and most viruses). ... Cell biology (also called cellular biology or cytology, from the Greek kytos, container) is an academic discipline which studies cells. ... An oncogene is a gene that can cause a cell to develop into a tumor cell, possibly resulting in cancer. ... A tumor suppressor gene is a gene that reduces the probability that a cell in a multicellular organism will turn into a tumor cell. ... In biology, apoptosis (from the Greek words apo = from and ptosis = falling, pronounced ap-a-tow-sis[1]) is one of the main types of programmed cell death (PCD). ...

DNA microarrays can be used to determine if oncogenes or tumor repressor genes have been mutated. Possibly in the future tumors can be treated better by using DNA microarrays to determine the exact characteristics of the tumor. A DNA microarray, the different colours indicate relative expression of different genes. ...

See also

• Tumor antigens
• Carcinoma
• Sarcoma
• Lymphoma
• Leukemia
• Polyp
• Papilloma