Pancreatic Neoplasms: Tumors or cancer of the PANCREAS. Depending on the types of ISLET CELLS present in the tumors, various hormones can be secreted: GLUCAGON from PANCREATIC ALPHA CELLS; INSULIN from PANCREATIC BETA CELLS; and SOMATOSTATIN from the SOMATOSTATIN-SECRETING CELLS. Most are malignant except the insulin-producing tumors (INSULINOMA).Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Neoplasms, Cystic, Mucinous, and Serous: Neoplasms containing cyst-like formations or producing mucin or serum.Skin Neoplasms: Tumors or cancer of the SKIN.Neoplasms, Multiple Primary: Two or more abnormal growths of tissue occurring simultaneously and presumed to be of separate origin. The neoplasms may be histologically the same or different, and may be found in the same or different sites.Kidney Neoplasms: Tumors or cancers of the KIDNEY.Neoplasms, Second Primary: Abnormal growths of tissue that follow a previous neoplasm but are not metastases of the latter. The second neoplasm may have the same or different histological type and can occur in the same or different organs as the previous neoplasm but in all cases arises from an independent oncogenic event. The development of the second neoplasm may or may not be related to the treatment for the previous neoplasm since genetic risk or predisposing factors may actually be the cause.Adenocarcinoma, Mucinous: An adenocarcinoma producing mucin in significant amounts. (From Dorland, 27th ed)Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Myeloproliferative Disorders: Conditions which cause proliferation of hemopoietically active tissue or of tissue which has embryonic hemopoietic potential. They all involve dysregulation of multipotent MYELOID PROGENITOR CELLS, most often caused by a mutation in the JAK2 PROTEIN TYROSINE KINASE.DNA, Neoplasm: DNA present in neoplastic tissue.Lung Neoplasms: Tumors or cancer of the LUNG.Parotid Neoplasms: Tumors or cancer of the PAROTID GLAND.Cystadenoma: A benign neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. In some instances, considerable portions of the neoplasm, or even the entire mass, may be cystic. (Stedman, 25th ed)Neoplasms, Connective and Soft Tissue: Neoplasms developing from some structure of the connective and subcutaneous tissue. The concept does not refer to neoplasms located in connective or soft tissue.Neoplasms, Plasma Cell: Neoplasms associated with a proliferation of a single clone of PLASMA CELLS and characterized by the secretion of PARAPROTEINS.Appendiceal Neoplasms: Tumors or cancer of the APPENDIX.Liver Neoplasms: Tumors or cancer of the LIVER.Cystadenoma, Mucinous: A multilocular tumor with mucin secreting epithelium. They are most often found in the ovary, but are also found in the pancreas, appendix, and rarely, retroperitoneal and in the urinary bladder. They are considered to have low-grade malignant potential.Ovarian Neoplasms: Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.Endocrine Gland Neoplasms: Tumors or cancer of the ENDOCRINE GLANDS.Gastrointestinal Neoplasms: Tumors or cancer of the GASTROINTESTINAL TRACT, from the MOUTH to the ANAL CANAL.Carcinoma, Pancreatic Ductal: Carcinoma that arises from the PANCREATIC DUCTS. It accounts for the majority of cancers derived from the PANCREAS.Neoplasms, Experimental: Experimentally induced new abnormal growth of TISSUES in animals to provide models for studying human neoplasms.Neoplasms, Vascular Tissue: Neoplasms composed of vascular tissue. This concept does not refer to neoplasms located in blood vessels.Eye Neoplasms: Tumors or cancer of the EYE.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Nose Neoplasms: Tumors or cancer of the NOSE.Salivary Gland Neoplasms: Tumors or cancer of the SALIVARY GLANDS.Neoplasms, Radiation-Induced: Tumors, cancer or other neoplasms produced by exposure to ionizing or non-ionizing radiation.Adenocarcinoma, Papillary: An adenocarcinoma containing finger-like processes of vascular connective tissue covered by neoplastic epithelium, projecting into cysts or the cavity of glands or follicles. It occurs most frequently in the ovary and thyroid gland. (Stedman, 25th ed)Carcinoma, Papillary: A malignant neoplasm characterized by the formation of numerous, irregular, finger-like projections of fibrous stroma that is covered with a surface layer of neoplastic epithelial cells. (Stedman, 25th ed)Testicular Neoplasms: Tumors or cancer of the TESTIS. Germ cell tumors (GERMINOMA) of the testis constitute 95% of all testicular neoplasms.Neoplasms, Muscle Tissue: Neoplasms composed of muscle tissue: skeletal, cardiac, or smooth. The concept does not refer to neoplasms located in muscles.Neoplasms, Glandular and Epithelial: Neoplasms composed of glandular tissue, an aggregation of epithelial cells that elaborate secretions, and of any type of epithelium itself. The concept does not refer to neoplasms located in the various glands or in epithelial tissue.Cystadenocarcinoma, Mucinous: A malignant cystic or semisolid tumor most often occurring in the ovary. Rarely, one is solid. This tumor may develop from a mucinous cystadenoma, or it may be malignant at the onset. The cysts are lined with tall columnar epithelial cells; in others, the epithelium consists of many layers of cells that have lost normal structure entirely. In the more undifferentiated tumors, one may see sheets and nests of tumor cells that have very little resemblance to the parent structure. (Hughes, Obstetric-Gynecologic Terminology, 1972, p184)Adenoma: A benign epithelial tumor with a glandular organization.Soft Tissue Neoplasms: Neoplasms of whatever cell type or origin, occurring in the extraskeletal connective tissue framework of the body including the organs of locomotion and their various component structures, such as nerves, blood vessels, lymphatics, etc.Hematologic Neoplasms: Neoplasms located in the blood and blood-forming tissue (the bone marrow and lymphatic tissue). The commonest forms are the various types of LEUKEMIA, of LYMPHOMA, and of the progressive, life-threatening forms of the MYELODYSPLASTIC SYNDROMES.Neoplasm Proteins: Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.Uterine Neoplasms: Tumors or cancer of the UTERUS.Intestinal Neoplasms: Tumors or cancer of the INTESTINES.Neoplasms, Adnexal and Skin Appendage: Neoplasms composed of sebaceous or sweat gland tissue or tissue of other skin appendages. The concept does not refer to neoplasms located in the sebaceous or sweat glands or in the other skin appendages.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Vascular Neoplasms: Neoplasms located in the vasculature system, such as ARTERIES and VEINS. They are differentiated from neoplasms of vascular tissue (NEOPLASMS, VASCULAR TISSUE), such as ANGIOFIBROMA or HEMANGIOMA.Sweat Gland NeoplasmsLymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Bone Neoplasms: Tumors or cancer located in bone tissue or specific BONES.Palatal Neoplasms: Tumors or cancer of the PALATE, including those of the hard palate, soft palate and UVULA.Neoplasms, Complex and Mixed: Neoplasms composed of more than one type of neoplastic tissue.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Mandibular Neoplasms: Tumors or cancer of the MANDIBLE.Cystadenocarcinoma: A malignant neoplasm derived from glandular epithelium, in which cystic accumulations of retained secretions are formed. The neoplastic cells manifest varying degrees of anaplasia and invasiveness, and local extension and metastases occur. Cystadenocarcinomas develop frequently in the ovaries, where pseudomucinous and serous types are recognized. (Stedman, 25th ed)Bile Duct Neoplasms: Tumors or cancer of the BILE DUCTS.Neoplasm Invasiveness: Ability of neoplasms to infiltrate and actively destroy surrounding tissue.Thymus Neoplasms: Tumors or cancer of the THYMUS GLAND.Splenic Neoplasms: Tumors or cancer of the SPLEEN.Heart Neoplasms: Tumors in any part of the heart. They include primary cardiac tumors and metastatic tumors to the heart. Their interference with normal cardiac functions can cause a wide variety of symptoms including HEART FAILURE; CARDIAC ARRHYTHMIAS; or EMBOLISM.Cystadenoma, Serous: A cystic tumor of the ovary, containing thin, clear, yellow serous fluid and varying amounts of solid tissue, with a malignant potential several times greater than that of mucinous cystadenoma (CYSTADENOMA, MUCINOUS). It can be unilocular, parvilocular, or multilocular. It is often bilateral and papillary. The cysts may vary greatly in size. (Dorland, 27th ed; from Hughes, Obstetric-Gynecologic Terminology, 1972)Colonic Neoplasms: Tumors or cancer of the COLON.Maxillary Neoplasms: Cancer or tumors of the MAXILLA or upper jaw.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Dog Diseases: Diseases of the domestic dog (Canis familiaris). This term does not include diseases of wild dogs, WOLVES; FOXES; and other Canidae for which the heading CARNIVORA is used.Anal Gland Neoplasms: Tumors or cancer of the anal gland.Neoplasms, Germ Cell and Embryonal: Neoplasms composed of primordial GERM CELLS of embryonic GONADS or of elements of the germ layers of the EMBRYO, MAMMALIAN. The concept does not refer to neoplasms located in the gonads or present in an embryo or FETUS.Bone Marrow Neoplasms: Neoplasms located in the bone marrow. They are differentiated from neoplasms composed of bone marrow cells, such as MULTIPLE MYELOMA. Most bone marrow neoplasms are metastatic.Neoplasms, Adipose Tissue: Neoplasms composed of fatty tissue or connective tissue made up of fat cells in a meshwork of areolar tissue. The concept does not refer to neoplasms located in adipose tissue.Colorectal Neoplasms: Tumors or cancer of the COLON or the RECTUM or both. Risk factors for colorectal cancer include chronic ULCERATIVE COLITIS; FAMILIAL POLYPOSIS COLI; exposure to ASBESTOS; and irradiation of the CERVIX UTERI.Meningeal Neoplasms: Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.Duodenal Neoplasms: Tumors or cancer of the DUODENUM.Adrenal Cortex Neoplasms: Tumors or cancers of the ADRENAL CORTEX.Mouth Neoplasms: Tumors or cancer of the MOUTH.Mediastinal Neoplasms: Tumors or cancer of the MEDIASTINUM.Tongue Neoplasms: Tumors or cancer of the TONGUE.Ileal Neoplasms: Tumors or cancer in the ILEUM region of the small intestine (INTESTINE, SMALL).Stomach Neoplasms: Tumors or cancer of the STOMACH.Urinary Bladder Neoplasms: Tumors or cancer of the URINARY BLADDER.Carcinoma, Acinar Cell: A malignant tumor arising from secreting cells of a racemose gland, particularly the salivary glands. Racemose (Latin racemosus, full of clusters) refers, as does acinar (Latin acinus, grape), to small saclike dilatations in various glands. Acinar cell carcinomas are usually well differentiated and account for about 13% of the cancers arising in the parotid gland. Lymph node metastasis occurs in about 16% of cases. Local recurrences and distant metastases many years after treatment are common. This tumor appears in all age groups and is most common in women. (Stedman, 25th ed; Holland et al., Cancer Medicine, 3d ed, p1240; from DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p575)Spinal Cord Neoplasms: Benign and malignant neoplasms which occur within the substance of the spinal cord (intramedullary neoplasms) or in the space between the dura and spinal cord (intradural extramedullary neoplasms). The majority of intramedullary spinal tumors are primary CNS neoplasms including ASTROCYTOMA; EPENDYMOMA; and LIPOMA. Intramedullary neoplasms are often associated with SYRINGOMYELIA. The most frequent histologic types of intradural-extramedullary tumors are MENINGIOMA and NEUROFIBROMA.Vaginal Neoplasms: Tumors or cancer of the VAGINA.Adenoma, Oxyphilic: A usually benign glandular tumor composed of oxyphil cells, large cells with small irregular nuclei and dense acidophilic granules due to the presence of abundant MITOCHONDRIA. Oxyphil cells, also known as oncocytes, are found in oncocytomas of the kidney, salivary glands, and endocrine glands. In the thyroid gland, oxyphil cells are known as Hurthle cells and Askanazy cells.Neoplasm Recurrence, Local: The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.Nervous System Neoplasms: Benign and malignant neoplastic processes arising from or involving components of the central, peripheral, and autonomic nervous systems, cranial nerves, and meninges. Included in this category are primary and metastatic nervous system neoplasms.Janus Kinase 2: A Janus kinase subtype that is involved in signaling from GROWTH HORMONE RECEPTORS; PROLACTIN RECEPTORS; and a variety of CYTOKINE RECEPTORS such as ERYTHROPOIETIN RECEPTORS and INTERLEUKIN RECEPTORS. Dysregulation of Janus kinase 2 due to GENETIC TRANSLOCATIONS have been associated with a variety of MYELOPROLIFERATIVE DISORDERS.Neoplasm Metastasis: The transfer of a neoplasm from one organ or part of the body to another remote from the primary site.Muscle Neoplasms: Tumors or cancer located in muscle tissue or specific muscles. They are differentiated from NEOPLASMS, MUSCLE TISSUE which are neoplasms composed of skeletal, cardiac, or smooth muscle tissue, such as MYOSARCOMA or LEIOMYOMA.Liver Neoplasms, Experimental: Experimentally induced tumors of the LIVER.Hemangiosarcoma: A rare malignant neoplasm characterized by rapidly proliferating, extensively infiltrating, anaplastic cells derived from blood vessels and lining irregular blood-filled or lumpy spaces. (Stedman, 25th ed)Carcinoma: A malignant neoplasm made up of epithelial cells tending to infiltrate the surrounding tissues and give rise to metastases. It is a histological type of neoplasm but is often wrongly used as a synonym for "cancer." (From Dorland, 27th ed)Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Myelodysplastic-Myeloproliferative Diseases: Clonal myeloid disorders that possess both dysplastic and proliferative features but are not properly classified as either MYELODYSPLASTIC SYNDROMES or MYELOPROLIFERATIVE DISORDERS.Pancreatectomy: Surgical removal of the pancreas. (Dorland, 28th ed)Peripheral Nervous System Neoplasms: Neoplasms which arise from peripheral nerve tissue. This includes NEUROFIBROMAS; SCHWANNOMAS; GRANULAR CELL TUMORS; and malignant peripheral NERVE SHEATH NEOPLASMS. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp1750-1)Cerebral Ventricle Neoplasms: Neoplasms located in the brain ventricles, including the two lateral, the third, and the fourth ventricle. Ventricular tumors may be primary (e.g., CHOROID PLEXUS NEOPLASMS and GLIOMA, SUBEPENDYMAL), metastasize from distant organs, or occur as extensions of locally invasive tumors from adjacent brain structures.Paranasal Sinus Neoplasms: Tumors or cancer of the PARANASAL SINUSES.Pleural Neoplasms: Neoplasms of the thin serous membrane that envelopes the lungs and lines the thoracic cavity. Pleural neoplasms are exceedingly rare and are usually not diagnosed until they are advanced because in the early stages they produce no symptoms.Breast Neoplasms: Tumors or cancer of the human BREAST.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Common Bile Duct Neoplasms: Tumor or cancer of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Orbital Neoplasms: Neoplasms of the bony orbit and contents except the eyeball.Abdominal NeoplasmsCerebellar Neoplasms: Primary or metastatic neoplasms of the CEREBELLUM. Tumors in this location frequently present with ATAXIA or signs of INTRACRANIAL HYPERTENSION due to obstruction of the fourth ventricle. Common primary cerebellar tumors include fibrillary ASTROCYTOMA and cerebellar HEMANGIOBLASTOMA. The cerebellum is a relatively common site for tumor metastases from the lung, breast, and other distant organs. (From Okazaki & Scheithauer, Atlas of Neuropathology, 1988, p86 and p141)Lipoma: A benign tumor composed of fat cells (ADIPOCYTES). It can be surrounded by a thin layer of connective tissue (encapsulated), or diffuse without the capsule.Facial NeoplasmsRetrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Neoplasms by Site: A collective term for precoordinated organ/neoplasm headings locating neoplasms by organ, as BRAIN NEOPLASMS; DUODENAL NEOPLASMS; LIVER NEOPLASMS; etc.Bronchial Neoplasms: Tumors or cancer of the BRONCHI.Peritoneal Neoplasms: Tumors or cancer of the PERITONEUM.Histiocytic Disorders, Malignant: Distinctive neoplastic disorders of histiocytes. Included are malignant neoplasms of MACROPHAGES and DENDRITIC CELLS.Urogenital Neoplasms: Tumors or cancer of the UROGENITAL SYSTEM in either the male or the female.Spinal NeoplasmsSkull Neoplasms: Neoplasms of the bony part of the skull.Vulvar Neoplasms: Tumors or cancer of the VULVA.Neoplasms, Neuroepithelial: Neoplasms composed of neuroepithelial cells, which have the capacity to differentiate into NEURONS, oligodendrocytes, and ASTROCYTES. The majority of craniospinal tumors are of neuroepithelial origin. (From Dev Biol 1998 Aug 1;200(1):1-5)Ear Neoplasms: Tumors or cancer of any part of the hearing and equilibrium system of the body (the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR).Lip Neoplasms: Tumors or cancer of the LIP.Fibroma: A benign tumor of fibrous or fully developed connective tissue.Neoplasm Transplantation: Experimental transplantation of neoplasms in laboratory animals for research purposes.Adrenal Gland Neoplasms: Tumors or cancer of the ADRENAL GLANDS.Pelvic Neoplasms: Tumors or cancer of the pelvic region.Gingival NeoplasmsGallbladder Neoplasms: Tumors or cancer of the gallbladder.Neoplasm Seeding: The local implantation of tumor cells by contamination of instruments and surgical equipment during and after surgical resection, resulting in local growth of the cells and tumor formation.Neoplasms, Fibroepithelial: Neoplasms composed of fibrous and epithelial tissue. The concept does not refer to neoplasms located in fibrous tissue or epithelium.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Respiratory Tract NeoplasmsNeoplasms, Connective Tissue: Neoplasms composed of connective tissue, including elastic, mucous, reticular, osseous, and cartilaginous tissue. The concept does not refer to neoplasms located in connective tissue.Neuroendocrine Tumors: Tumors whose cells possess secretory granules and originate from the neuroectoderm, i.e., the cells of the ectoblast or epiblast that program the neuroendocrine system. Common properties across most neuroendocrine tumors include ectopic hormone production (often via APUD CELLS), the presence of tumor-associated antigens, and isozyme composition.Neoplasm Grading: Methods which attempt to express in replicable terms the level of CELL DIFFERENTIATION in neoplasms as increasing ANAPLASIA correlates with the aggressiveness of the neoplasm.Primary Myelofibrosis: A de novo myeloproliferation arising from an abnormal stem cell. It is characterized by the replacement of bone marrow by fibrous tissue, a process that is mediated by CYTOKINES arising from the abnormal clone.Polycythemia Vera: A myeloproliferative disorder of unknown etiology, characterized by abnormal proliferation of all hematopoietic bone marrow elements and an absolute increase in red cell mass and total blood volume, associated frequently with splenomegaly, leukocytosis, and thrombocythemia. Hematopoiesis is also reactive in extramedullary sites (liver and spleen). In time myelofibrosis occurs.Thrombocythemia, Essential: A clinical syndrome characterized by repeated spontaneous hemorrhages and a remarkable increase in the number of circulating platelets.RNA, Neoplasm: RNA present in neoplastic tissue.Trophoblastic Neoplasms: Trophoblastic growth, which may be gestational or nongestational in origin. Trophoblastic neoplasia resulting from pregnancy is often described as gestational trophoblastic disease to distinguish it from germ cell tumors which frequently show trophoblastic elements, and from the trophoblastic differentiation which sometimes occurs in a wide variety of epithelial cancers. Gestational trophoblastic growth has several forms, including HYDATIDIFORM MOLE and CHORIOCARCINOMA. (From Holland et al., Cancer Medicine, 3d ed, p1691)Hemangioma: A vascular anomaly due to proliferation of BLOOD VESSELS that forms a tumor-like mass. The common types involve CAPILLARIES and VEINS. It can occur anywhere in the body but is most frequently noticed in the SKIN and SUBCUTANEOUS TISSUE. (from Stedman, 27th ed, 2000)Head and Neck Neoplasms: Soft tissue tumors or cancer arising from the mucosal surfaces of the LIP; oral cavity; PHARYNX; LARYNX; and cervical esophagus. Other sites included are the NOSE and PARANASAL SINUSES; SALIVARY GLANDS; THYROID GLAND and PARATHYROID GLANDS; and MELANOMA and non-melanoma skin cancers of the head and neck. (from Holland et al., Cancer Medicine, 4th ed, p1651)Rodent Diseases: Diseases of rodents of the order RODENTIA. This term includes diseases of Sciuridae (squirrels), Geomyidae (gophers), Heteromyidae (pouched mice), Castoridae (beavers), Cricetidae (rats and mice), Muridae (Old World rats and mice), Erethizontidae (porcupines), and Caviidae (guinea pigs).Thoracic NeoplasmsCecal Neoplasms: Tumors or cancer of the CECUM.Leukemia, B-Cell: A malignant disease of the B-LYMPHOCYTES in the bone marrow and/or blood.Hemangioendothelioma: A neoplasm derived from blood vessels, characterized by numerous prominent endothelial cells that occur singly, in aggregates, and as the lining of congeries of vascular tubes or channels. Hemangioendotheliomas are relatively rare and are of intermediate malignancy (between benign hemangiomas and conventional angiosarcomas). They affect men and women about equally and rarely develop in childhood. (From Stedman, 25th ed; Holland et al., Cancer Medicine, 3d ed, p1866)Adenoma, Pleomorphic: A benign, slow-growing tumor, most commonly of the salivary gland, occurring as a small, painless, firm nodule, usually of the parotid gland, but also found in any major or accessory salivary gland anywhere in the oral cavity. It is most often seen in women in the fifth decade. Histologically, the tumor presents a variety of cells: cuboidal, columnar, and squamous cells, showing all forms of epithelial growth. (Dorland, 27th ed)Digestive System Neoplasms: Tumors or cancer of the DIGESTIVE SYSTEM.Tracheal NeoplasmsAdenocarcinoma, Follicular: An adenocarcinoma of the thyroid gland, in which the cells are arranged in the form of follicles. (From Dorland, 27th ed)Jejunal Neoplasms: Tumors or cancer in the JEJUNUM region of the small intestine (INTESTINE, SMALL).Carcinoma, Neuroendocrine: A group of carcinomas which share a characteristic morphology, often being composed of clusters and trabecular sheets of round "blue cells", granular chromatin, and an attenuated rim of poorly demarcated cytoplasm. Neuroendocrine tumors include carcinoids, small ("oat") cell carcinomas, medullary carcinoma of the thyroid, Merkel cell tumor, cutaneous neuroendocrine carcinoma, pancreatic islet cell tumors, and pheochromocytoma. Neurosecretory granules are found within the tumor cells. (Segen, Dictionary of Modern Medicine, 1992)Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Neurilemmoma: A neoplasm that arises from SCHWANN CELLS of the cranial, peripheral, and autonomic nerves. Clinically, these tumors may present as a cranial neuropathy, abdominal or soft tissue mass, intracranial lesion, or with spinal cord compression. Histologically, these tumors are encapsulated, highly vascular, and composed of a homogenous pattern of biphasic fusiform-shaped cells that may have a palisaded appearance. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp964-5)Biopsy, Fine-Needle: Using fine needles (finer than 22-gauge) to remove tissue or fluid specimens from the living body for examination in the pathology laboratory and for disease diagnosis.Central Nervous System Neoplasms: Benign and malignant neoplastic processes that arise from or secondarily involve the brain, spinal cord, or meninges.Sarcoma: A connective tissue neoplasm formed by proliferation of mesodermal cells; it is usually highly malignant.Carcinosarcoma: A malignant neoplasm that contains elements of carcinoma and sarcoma so extensively intermixed as to indicate neoplasia of epithelial and mesenchymal tissue. (Stedman, 25th ed)Cyst Fluid: Liquid material found in epithelial-lined closed cavities or sacs.Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.Adenoma, Liver Cell: A benign epithelial tumor of the LIVER.Pituitary Neoplasms: Neoplasms which arise from or metastasize to the PITUITARY GLAND. The majority of pituitary neoplasms are adenomas, which are divided into non-secreting and secreting forms. Hormone producing forms are further classified by the type of hormone they secrete. Pituitary adenomas may also be characterized by their staining properties (see ADENOMA, BASOPHIL; ADENOMA, ACIDOPHIL; and ADENOMA, CHROMOPHOBE). Pituitary tumors may compress adjacent structures, including the HYPOTHALAMUS, several CRANIAL NERVES, and the OPTIC CHIASM. Chiasmal compression may result in bitemporal HEMIANOPSIA.Histiocytic Sarcoma: Malignant neoplasms composed of MACROPHAGES or DENDRITIC CELLS. Most histiocytic sarcomas present as localized tumor masses without a leukemic phase. Though the biological behavior of these neoplasms resemble lymphomas, their cell lineage is histiocytic not lymphoid.Keratoacanthoma: A benign, non-neoplastic, usually self-limiting epithelial lesion closely resembling squamous cell carcinoma clinically and histopathologically. It occurs in solitary, multiple, and eruptive forms. The solitary and multiple forms occur on sunlight exposed areas and are identical histologically; they affect primarily white males. The eruptive form usually involves both sexes and appears as a generalized papular eruption.Pseudomyxoma Peritonei: A condition characterized by poorly-circumscribed gelatinous masses filled with malignant mucin-secreting cells. Forty-five percent of pseudomyxomas arise from the ovary, usually in a mucinous cystadenocarcinoma (CYSTADENOCARCINOMA, MUCINOUS), which has prognostic significance. Pseudomyxoma peritonei must be differentiated from mucinous spillage into the peritoneum by a benign mucocele of the appendix. (Segen, Dictionary of Modern Medicine, 1992)Carcinogenicity Tests: Tests to experimentally measure the tumor-producing/cancer cell-producing potency of an agent by administering the agent (e.g., benzanthracenes) and observing the quantity of tumors or the cell transformation developed over a given period of time. The carcinogenicity value is usually measured as milligrams of agent administered per tumor developed. Though this test differs from the DNA-repair and bacterial microsome MUTAGENICITY TESTS, researchers often attempt to correlate the finding of carcinogenicity values and mutagenicity values.Leukemia: A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemias were originally termed acute or chronic based on life expectancy but now are classified according to cellular maturity. Acute leukemias consist of predominately immature cells; chronic leukemias are composed of more mature cells. (From The Merck Manual, 2006)Genital Neoplasms, Male: Tumor or cancer of the MALE GENITALIA.Infratentorial Neoplasms: Intracranial tumors originating in the region of the brain inferior to the tentorium cerebelli, which contains the cerebellum, fourth ventricle, cerebellopontine angle, brain stem, and related structures. Primary tumors of this region are more frequent in children, and may present with ATAXIA; CRANIAL NERVE DISEASES; vomiting; HEADACHE; HYDROCEPHALUS; or other signs of neurologic dysfunction. Relatively frequent histologic subtypes include TERATOMA; MEDULLOBLASTOMA; GLIOBLASTOMA; ASTROCYTOMA; EPENDYMOMA; CRANIOPHARYNGIOMA; and choroid plexus papilloma (PAPILLOMA, CHOROID PLEXUS).Biliary Tract Neoplasms: Tumors or cancer in the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Iris Neoplasms: Tumors of the iris characterized by increased pigmentation of melanocytes. Iris nevi are composed of proliferated melanocytes and are associated with neurofibromatosis and malignant melanoma of the choroid and ciliary body. Malignant melanoma of the iris often originates from preexisting nevi.Precancerous Conditions: Pathological processes that tend eventually to become malignant. (From Dorland, 27th ed)Urethral Neoplasms: Cancer or tumors of the URETHRA. Benign epithelial tumors of the urethra usually consist of squamous and transitional cells. Primary urethral carcinomas are rare and typically of squamous cells. Urethral carcinoma is the only urological malignancy that is more common in females than in males.Laryngeal Neoplasms: Cancers or tumors of the LARYNX or any of its parts: the GLOTTIS; EPIGLOTTIS; LARYNGEAL CARTILAGES; LARYNGEAL MUSCLES; and VOCAL CORDS.Granulosa Cell Tumor: A neoplasm composed entirely of GRANULOSA CELLS, occurring mostly in the OVARY. In the adult form, it may contain some THECA CELLS. This tumor often produces ESTRADIOL and INHIBIN. The excess estrogen exposure can lead to other malignancies in women and PRECOCIOUS PUBERTY in girls. In rare cases, granulosa cell tumors have been identified in the TESTES.Mammary Neoplasms, Animal: Tumors or cancer of the MAMMARY GLAND in animals (MAMMARY GLANDS, ANIMAL).Perivascular Epithelioid Cell Neoplasms: A family of mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. These cells do not have a normal anatomic homolog. (From Fletcher CDM, et. al., World Health Organization Classification of Tumors: Pathology and Genetics of Tumors of Soft Tissue and Bone, 2002).Rats, Inbred F344Carcinoma, Adenoid Cystic: Carcinoma characterized by bands or cylinders of hyalinized or mucinous stroma separating or surrounded by nests or cords of small epithelial cells. When the cylinders occur within masses of epithelial cells, they give the tissue a perforated, sievelike, or cribriform appearance. Such tumors occur in the mammary glands, the mucous glands of the upper and lower respiratory tract, and the salivary glands. They are malignant but slow-growing, and tend to spread locally via the nerves. (Dorland, 27th ed)Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Biopsy, Needle: Removal and examination of tissue obtained through a transdermal needle inserted into the specific region, organ, or tissue being analyzed.Immunoenzyme Techniques: Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.Astrocytoma: Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Mesenchymoma: A mixed mesenchymal tumor composed of two or more mesodermal cellular elements not commonly associated, not counting fibrous tissue as one of the elements. Mesenchymomas are widely distributed in the body and about 75% are malignant. (Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1866)Rectal Neoplasms: Tumors or cancer of the RECTUM.Lymphoma, T-Cell: A group of heterogeneous lymphoid tumors representing malignant transformations of T-lymphocytes.Esophageal Neoplasms: Tumors or cancer of the ESOPHAGUS.Cat Diseases: Diseases of the domestic cat (Felis catus or F. domesticus). This term does not include diseases of the so-called big cats such as CHEETAHS; LIONS; tigers, cougars, panthers, leopards, and other Felidae for which the heading CARNIVORA is used.Genital Neoplasms, Female: Tumor or cancer of the female reproductive tract (GENITALIA, FEMALE).Submandibular Gland NeoplasmsPapilloma: A circumscribed benign epithelial tumor projecting from the surrounding surface; more precisely, a benign epithelial neoplasm consisting of villous or arborescent outgrowths of fibrovascular stroma covered by neoplastic cells. (Stedman, 25th ed)Gene Expression Regulation, Neoplastic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.Myoepithelioma: A usually benign tumor made up predominantly of myoepithelial cells.Prostatic Neoplasms: Tumors or cancer of the PROSTATE.Eyelid Neoplasms: Tumors of cancer of the EYELIDS.Keratin-7: A type II keratin found associated with KERATIN-19 in ductal epithelia and gastrointestinal epithelia.Hypothalamic Neoplasms: Benign and malignant tumors of the HYPOTHALAMUS. Pilocytic astrocytomas and hamartomas are relatively frequent histologic types. Neoplasms of the hypothalamus frequently originate from adjacent structures, including the OPTIC CHIASM, optic nerve (see OPTIC NERVE NEOPLASMS), and pituitary gland (see PITUITARY NEOPLASMS). Relatively frequent clinical manifestations include visual loss, developmental delay, macrocephaly, and precocious puberty. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2051)Oligodendroglioma: A relatively slow-growing glioma that is derived from oligodendrocytes and tends to occur in the cerebral hemispheres, thalamus, or lateral ventricle. They may present at any age, but are most frequent in the third to fifth decades, with an earlier incidence peak in the first decade. Histologically, these tumors are encapsulated, relatively avascular, and tend to form cysts and microcalcifications. Neoplastic cells tend to have small round nuclei surrounded by unstained nuclei. The tumors may vary from well-differentiated to highly anaplastic forms. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2052; Adams et al., Principles of Neurology, 6th ed, p655)Histiocytoma, Benign Fibrous: A benign tumor composed, wholly or in part, of cells with the morphologic characteristics of HISTIOCYTES and with various fibroblastic components. Fibrous histiocytomas can occur anywhere in the body. When they occur in the skin, they are called dermatofibromas or sclerosing hemangiomas. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 5th ed, p1747)Meningioma: A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)Keratins: A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION.Carcinoid Tumor: A usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface. The tumor can occur anywhere in the gastrointestinal tract (and in the lungs and other sites); approximately 90% arise in the appendix. It is now established that these tumors are of neuroendocrine origin and derive from a primitive stem cell. (From Stedman, 25th ed & Holland et al., Cancer Medicine, 3d ed, p1182)Lymphoma, B-Cell: A group of heterogeneous lymphoid tumors generally expressing one or more B-cell antigens or representing malignant transformations of B-lymphocytes.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Maxillary Sinus Neoplasms: Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.