''See the cancer for the main article about malignant tumors.'' 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 biological tissue. This growth can be either malignant or benign. Malignant tumors are called cancer. Cancer has the potential to invade and destroy neighboring tissues and create metastasis. 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. Depending on tissue of origin, tumors may be: * Tumors of epithelium origin. ** squamous epithelium: squamous cell papilloma, squamous cell carcinoma ** transitional epithelium: transitional cell papilloma, transitional cell carcinoma ** basal cell (only in skin): basal cell carcinoma ** glandular epithelium: adenoma, cystadenoma, adenocarcinoma ** tubules epithelium (kidney): renal tubular adenoma, renal cell carcinoma (Grawitz tumor) ** hepatocytes: hepatocellular adenoma, hepatocellular carcinoma ** bile ducts epithelium: cholangiocellular adenoma, cholangiocellular carcinoma ** melanocytes: melanocytic nevus, malignant melanoma * Tumors of mesenchymal origin: ** connective tissue: *** fibroma, fibrosarcoma *** myxoma, myxosarcoma *** chondroma, chondrosarcoma *** osteoma, osteosarcoma (osteogenic sarcoma) *** lipoma, liposarcoma ** muscle: *** leiomyoma, leiomyosarcoma *** rhabdomyoma, rhabdomyosarcoma ** endothelium: *** hemangioma (capillary h., cavernous h.), glomus tumor, hemangiosarcoma, Kaposi sarcoma *** lymphangioma, lymphangiosarcoma * Tumors of blood cells: ** hematopoietic cells: leukemia **lymphoid cells: non-Hodgkin lymphoma, Hodgkin lymphoma * Tumors of germ cells: ** Teratoma (mature teratoma, immature teratoma) An epithelial tumor is considered malignant if it penetrates the basal lamina and is considered benign if it does not. Tumors are caused by mutations in DNA of Cell biology. 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 gen is usually not enough for a tumor to occur. A combination of a number of mutations is necessary. DNA microarrays can be used to determine if oncogens or tumor repressor gens have been mutated. Possibly in the future tumors can be treated better by using DNA microarrays to determine the exact characteristics of the tumor. As people get older, they accumulate more mutations in their DNA. This means that the Prevalence (epidemiology) 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. ==See also== *Antigen#Tumor antigens *Carcinoma *Sarcoma *Lymphoma *Leukemia *Polyp (medicine) Oncology Anatomical pathology
== accoustic neuroma ==
See other meanings of words starting from letter:
Words begining with Tumor:
Tumor
Tumor
Tumor-suppressor_gene
Tumorogenisis
Tumors
Tumor_cell
Tumor_cells
Tumor_lysis_syndrome
Tumor_marker
Tumor_necrosis_factor
Tumor_necrosis_factor-alpha
Tumor_suppressor_gene
Tumor_supressor_gene
Tumor
''See the cancer for the main article about malignant tumors.'' 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 biological tissue. This growth can be either malignant or benign. Malignant tumors are called cancer. Cancer has the potential to invade and destroy neighboring tissues and create metastasis. 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. Depending on tissue of origin, tumors may be: * Tumors of epithelium origin. ** squamous epithelium: squamous cell papilloma, squamous cell carcinoma ** transitional epithelium: transitional cell papilloma, transitional cell carcinoma ** basal cell (only in skin): basal cell carcinoma ** glandular epithelium: adenoma, cystadenoma, adenocarcinoma ** tubules epithelium (kidney): renal tubular adenoma, renal cell carcinoma (Grawitz tumor) ** hepatocytes: hepatocellular adenoma, hepatocellular carcinoma ** bile ducts epithelium: cholangiocellular adenoma, cholangiocellular carcinoma ** melanocytes: melanocytic nevus, malignant melanoma * Tumors of mesenchymal origin: ** connective tissue: *** fibroma, fibrosarcoma *** myxoma, myxosarcoma *** chondroma, chondrosarcoma *** osteoma, osteosarcoma (osteogenic sarcoma) *** lipoma, liposarcoma ** muscle: *** leiomyoma, leiomyosarcoma *** rhabdomyoma, rhabdomyosarcoma ** endothelium: *** hemangioma (capillary h., cavernous h.), glomus tumor, hemangiosarcoma, Kaposi sarcoma *** lymphangioma, lymphangiosarcoma * Tumors of blood cells: ** hematopoietic cells: leukemia **lymphoid cells: non-Hodgkin lymphoma, Hodgkin lymphoma * Tumors of germ cells: ** Teratoma (mature teratoma, immature teratoma) An epithelial tumor is considered malignant if it penetrates the basal lamina and is considered benign if it does not. Tumors are caused by mutations in DNA of Cell biology. 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 gen is usually not enough for a tumor to occur. A combination of a number of mutations is necessary. DNA microarrays can be used to determine if oncogens or tumor repressor gens have been mutated. Possibly in the future tumors can be treated better by using DNA microarrays to determine the exact characteristics of the tumor. As people get older, they accumulate more mutations in their DNA. This means that the Prevalence (epidemiology) 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. ==See also== *Antigen#Tumor antigens *Carcinoma *Sarcoma *Lymphoma *Leukemia *Polyp (medicine) Oncology Anatomical pathology
Tumor
== accoustic neuroma ==
See other meanings of words starting from letter:
T
TA | TB | TC | TD | TE | TF | TG | TH | TI | TJ | TK | TL | TŁ | TM | TN | TO | TP | TR | TS | TU | TW | TX | TY | TZ |Words begining with Tumor:
Tumor
Tumor
Tumor-suppressor_gene
Tumorogenisis
Tumors
Tumor_cell
Tumor_cells
Tumor_lysis_syndrome
Tumor_marker
Tumor_necrosis_factor
Tumor_necrosis_factor-alpha
Tumor_suppressor_gene
Tumor_supressor_gene
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