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.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.Thyroid Nodule: A small circumscribed mass in the THYROID GLAND that can be of neoplastic growth or non-neoplastic abnormality. It lacks a well-defined capsule or glandular architecture. Thyroid nodules are often benign but can be malignant. The growth of nodules can lead to a multinodular goiter (GOITER, NODULAR).Cytodiagnosis: Diagnosis of the type and, when feasible, the cause of a pathologic process by means of microscopic study of cells in an exudate or other form of body fluid. (Stedman, 26th ed)Thyroid Neoplasms: Tumors or cancer of the THYROID GLAND.Endosonography: Ultrasonography of internal organs using an ultrasound transducer sometimes mounted on a fiberoptic endoscope. In endosonography the transducer converts electronic signals into acoustic pulses or continuous waves and acts also as a receiver to detect reflected pulses from within the organ. An audiovisual-electronic interface converts the detected or processed echo signals, which pass through the electronics of the instrument, into a form that the technologist can evaluate. The procedure should not be confused with ENDOSCOPY which employs a special instrument called an endoscope. The "endo-" of endosonography refers to the examination of tissue within hollow organs, with reference to the usual ultrasonography procedure which is performed externally or transcutaneously.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Thyroid Gland: A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.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)False Negative Reactions: Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Endoscopic Ultrasound-Guided Fine Needle Aspiration: Conducting a fine needle biopsy with the aid of ENDOSCOPIC ULTRASONOGRAPHY.Adenocarcinoma, Follicular: An adenocarcinoma of the thyroid gland, in which the cells are arranged in the form of follicles. (From Dorland, 27th ed)Thyroidectomy: Surgical removal of the thyroid gland. (Dorland, 28th ed)Thyroid Diseases: Pathological processes involving the THYROID GLAND.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 Askenazy cells.Image-Guided Biopsy: Conducting a biopsy procedure with the aid of a MEDICAL IMAGING modality.Retrospective 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.Ultrasonography, Interventional: The use of ultrasound to guide minimally invasive surgical procedures such as needle ASPIRATION BIOPSY; DRAINAGE; etc. Its widest application is intravascular ultrasound imaging but it is useful also in urology and intra-abdominal conditions.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Histocytological Preparation Techniques: Methods of preparing cells or tissues for examination and study of their origin, structure, function, or pathology. The methods include preservation, fixation, sectioning, staining, replica, or other technique to allow for viewing using a microscope.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).Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Breast Neoplasms: Tumors or cancer of the human BREAST.Parotid Neoplasms: Tumors or cancer of the PAROTID GLAND.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.False Positive Reactions: Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Goiter, Nodular: An enlarged THYROID GLAND containing multiple nodules (THYROID NODULE), usually resulting from recurrent thyroid HYPERPLASIA and involution over many years to produce the irregular enlargement. Multinodular goiters may be nontoxic or may induce THYROTOXICOSIS.Sentinel Lymph Node Biopsy: A diagnostic procedure used to determine whether LYMPHATIC METASTASIS has occurred. The sentinel lymph node is the first lymph node to receive drainage from a neoplasm.Cyst Fluid: Liquid material found in epithelial-lined closed cavities or sacs.Diagnostic Errors: Incorrect diagnoses after clinical examination or technical diagnostic procedures.Tuberculosis, Lymph Node: Infection of the lymph nodes by tuberculosis. Tuberculous infection of the cervical lymph nodes is scrofula.Lymphatic Metastasis: Transfer of a neoplasm from its primary site to lymph nodes or to distant parts of the body by way of the lymphatic system.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.Breast Diseases: Pathological processes of the BREAST.Lymphatic Diseases: Diseases of LYMPH; LYMPH NODES; or LYMPHATIC VESSELS.Actinomycosis, Cervicofacial: A form of ACTINOMYCOSIS characterized by slow-growing inflammatory lesions of the lymph nodes that drain the mouth (lumpy jaw), reddening of the overlying skin, and intraperitoneal abscesses.Carcinoma, Papillary, Follicular: A thyroid neoplasm of mixed papillary and follicular arrangement. Its biological behavior and prognosis is the same as that of a papillary adenocarcinoma of the thyroid. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1271)Breast: In humans, one of the paired regions in the anterior portion of the THORAX. The breasts consist of the MAMMARY GLANDS, the SKIN, the MUSCLES, the ADIPOSE TISSUE, and the CONNECTIVE TISSUES.Neck: The part of a human or animal body connecting the HEAD to the rest of the body.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)Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Mediastinum: A membrane in the midline of the THORAX of mammals. It separates the lungs between the STERNUM in front and the VERTEBRAL COLUMN behind. It also surrounds the HEART, TRACHEA, ESOPHAGUS, THYMUS, and LYMPH NODES.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.Biopsy, Large-Core Needle: The use of needles usually larger than 14-gauge to remove tissue samples large enough to retain cellular architecture for pathology examination.Adenolymphoma: A benign tumor characterized histologically by tall columnar epithelium within a lymphoid tissue stroma. It is usually found in the salivary glands, especially the parotid.Cytological Techniques: Methods used to study CELLS.Axilla: Area of the human body underneath the SHOULDER JOINT, also known as the armpit or underarm.Ultrasonography, Mammary: Use of ultrasound for imaging the breast. The most frequent application is the diagnosis of neoplasms of the female breast.Frozen Sections: Thinly cut sections of frozen tissue specimens prepared with a cryostat or freezing microtome.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.Lymphadenitis: Inflammation of the lymph nodes.Abdominal NeoplasmsLymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Thyroiditis: Inflammatory diseases of the THYROID GLAND. Thyroiditis can be classified into acute (THYROIDITIS, SUPPURATIVE), subacute (granulomatous and lymphocytic), chronic fibrous (Riedel's), chronic lymphocytic (HASHIMOTO DISEASE), transient (POSTPARTUM THYROIDITIS), and other AUTOIMMUNE THYROIDITIS subtypes.Ultrasonography: The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.Adenocarcinoma, Mucinous: An adenocarcinoma producing mucin in significant amounts. (From Dorland, 27th ed)Pancreatic Cyst: A true cyst of the PANCREAS, distinguished from the much more common PANCREATIC PSEUDOCYST by possessing a lining of mucous EPITHELIUM. Pancreatic cysts are categorized as congenital, retention, neoplastic, parasitic, enterogenous, or dermoid. Congenital cysts occur more frequently as solitary cysts but may be multiple. Retention cysts are gross enlargements of PANCREATIC DUCTS secondary to ductal obstruction. (From Bockus Gastroenterology, 4th ed, p4145)Specimen Handling: Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Adenoma: A benign epithelial tumor with a glandular organization.Salivary Gland Neoplasms: Tumors or cancer of the SALIVARY GLANDS.Parotid DiseasesFasciitis: Inflammation of the fascia. There are three major types: 1, Eosinophilic fasciitis, an inflammatory reaction with eosinophilia, producing hard thickened skin with an orange-peel configuration suggestive of scleroderma and considered by some a variant of scleroderma; 2, Necrotizing fasciitis (FASCIITIS, NECROTIZING), a serious fulminating infection (usually by a beta hemolytic streptococcus) causing extensive necrosis of superficial fascia; 3, Nodular/Pseudosarcomatous /Proliferative fasciitis, characterized by a rapid growth of fibroblasts with mononuclear inflammatory cells and proliferating capillaries in soft tissue, often the forearm; it is not malignant but is sometimes mistaken for fibrosarcoma.Mediastinal Neoplasms: Tumors or cancer of the MEDIASTINUM.Hashimoto Disease: Chronic autoimmune thyroiditis, characterized by the presence of high serum thyroid AUTOANTIBODIES; GOITER; and HYPOTHYROIDISM.Carcinoma, Ductal, Breast: An invasive (infiltrating) CARCINOMA of the mammary ductal system (MAMMARY GLANDS) in the human BREAST.Endoscopy, Digestive System: Endoscopic examination, therapy or surgery of the digestive tract.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)Cell Biology: The study of the structure, behavior, growth, reproduction, and pathology of cells; and the function and chemistry of cellular components.Preoperative Care: Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Tuberculosis, Oral: Tuberculosis of the mouth, tongue, and salivary glands.Buruli Ulcer: A lesion in the skin and subcutaneous tissues due to infections by MYCOBACTERIUM ULCERANS. It was first reported in Uganda, Africa.Needles: Sharp instruments used for puncturing or suturing.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)Galectin 3: A multifunctional galactin initially discovered as a macrophage antigen that binds to IMMUNOGLOBULIN E, and as 29-35-kDa lectin that binds LAMININ. It is involved in a variety of biological events including interactions with galactose-containing glycoconjugates, cell proliferation, CELL DIFFERENTIATION, and APOPTOSIS.Lung Neoplasms: Tumors or cancer of the LUNG.Palpation: Application of fingers with light pressure to the surface of the body to determine consistence of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs.Cysts: Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.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)In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Leiomyoma, Epithelioid: A relatively rare smooth muscle tumor found most frequently in the wall of the gastrointestinal tract, especially in the stomach. It is similar to other smooth muscle tumors but may become very large and hemorrhage and exhibit small cystic areas. Simple excision is almost always curative. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1354)Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Mediastinal Diseases: Disorders of the mediastinum, general or unspecified.Onygenales: An order of fungi in the phylum ASCOMYCOTA containing many medically important species. There are four families and mitosporic (anamorphic) forms are prominent.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.Carcinoma, Lobular: A infiltrating (invasive) breast cancer, relatively uncommon, accounting for only 5%-10% of breast tumors in most series. It is often an area of ill-defined thickening in the breast, in contrast to the dominant lump characteristic of ductal carcinoma. It is typically composed of small cells in a linear arrangement with a tendency to grow around ducts and lobules. There is likelihood of axillary nodal involvement with metastasis to meningeal and serosal surfaces. (DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1205)Pancreas: A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.Sarcoma: A connective tissue neoplasm formed by proliferation of mesodermal cells; it is usually highly malignant.Bronchoscopy: Endoscopic examination, therapy or surgery of the bronchi.Central African Republic: A republic in central Africa south of CHAD and SUDAN, north of DEMOCRATIC REPUBLIC OF THE CONGO, and east of CAMEROON. The capital is Bangui.Image Cytometry: A technique encompassing morphometry, densitometry, neural networks, and expert systems that has numerous clinical and research applications and is particularly useful in anatomic pathology for the study of malignant lesions. The most common current application of image cytometry is for DNA analysis, followed by quantitation of immunohistochemical staining.Carcinoma, Islet Cell: A primary malignant neoplasm of the pancreatic ISLET CELLS. Usually it involves the non-INSULIN-producing cell types, the PANCREATIC ALPHA CELLS and the pancreatic delta cells (SOMATOSTATIN-SECRETING CELLS) in GLUCAGONOMA and SOMATOSTATINOMA, respectively.Melanoma: A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)Fibrocystic Breast Disease: A common and benign breast disease characterized by varying degree of fibrocystic changes in the breast tissue. There are three major patterns of morphological changes, including FIBROSIS, formation of CYSTS, and proliferation of glandular tissue (adenosis). The fibrocystic breast has a dense irregular, lumpy, bumpy consistency.Proto-Oncogene Proteins B-raf: A raf kinase subclass found at high levels in neuronal tissue. The B-raf Kinases are MAP kinase kinase kinases that have specificity for MAP KINASE KINASE 1 and MAP KINASE KINASE 2.Thyroiditis, Autoimmune: Inflammatory disease of the THYROID GLAND due to autoimmune responses leading to lymphocytic infiltration of the gland. It is characterized by the presence of circulating thyroid antigen-specific T-CELLS and thyroid AUTOANTIBODIES. The clinical signs can range from HYPOTHYROIDISM to THYROTOXICOSIS depending on the type of autoimmune thyroiditis.Immunophenotyping: Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.Mammography: Radiographic examination of the breast.Fibroadenoma: An adenoma containing fibrous tissue. It should be differentiated from ADENOFIBROMA which is a tumor composed of connective tissue (fibroma) containing glandular (adeno-) structures. (From Dorland, 27th ed)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)Gastrointestinal Neoplasms: Tumors or cancer of the GASTROINTESTINAL TRACT, from the MOUTH to the ANAL CANAL.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.Xeromammography: Xeroradiography of the breast.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)Paraffin Embedding: The infiltrating of tissue specimens with paraffin, as a supporting substance, to prepare for sectioning with a microtome.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Carcinoma, Medullary: A carcinoma composed mainly of epithelial elements with little or no stroma. Medullary carcinomas of the breast constitute 5%-7% of all mammary carcinomas; medullary carcinomas of the thyroid comprise 3%-10% of all thyroid malignancies. (From Dorland, 27th ed; DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1141; Segen, Dictionary of Modern Medicine, 1992)ThyroglobulinTissue Fixation: The technique of using FIXATIVES in the preparation of cytologic, histologic, or pathologic specimens for the purpose of maintaining the existing form and structure of all the constituent elements.Staining and Labeling: The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.Myoepithelioma: A usually benign tumor made up predominantly of myoepithelial cells.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Surgery, Computer-Assisted: Surgical procedures conducted with the aid of computers. This is most frequently used in orthopedic and laparoscopic surgery for implant placement and instrument guidance. Image-guided surgery interactively combines prior CT scans or MRI images with real-time video.Skin Neoplasms: Tumors or cancer of the SKIN.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)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.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.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Carcinoma, Squamous Cell: A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)Pneumothorax: An accumulation of air or gas in the PLEURAL CAVITY, which may occur spontaneously or as a result of trauma or a pathological process. The gas may also be introduced deliberately during PNEUMOTHORAX, ARTIFICIAL.Hyperplasia: An increase in the number of cells in a tissue or organ without tumor formation. It differs from HYPERTROPHY, which is an increase in bulk without an increase in the number of cells.Carcinoma in Situ: A lesion with cytological characteristics associated with invasive carcinoma but the tumor cells are confined to the epithelium of origin, without invasion of the basement membrane.Parotid Gland: The largest of the three pairs of SALIVARY GLANDS. They lie on the sides of the FACE immediately below and in front of the EAR.Lymphoma, Non-Hodgkin: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.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.Liver Neoplasms: Tumors or cancer of the LIVER.DNA, Neoplasm: DNA present in neoplastic tissue.Breast Neoplasms, Male: Any neoplasms of the male breast. These occur infrequently in males in developed countries, the incidence being about 1% of that in females.Pancreatic Diseases: Pathological processes of the PANCREAS.Gastrointestinal Stromal Tumors: All tumors in the GASTROINTESTINAL TRACT arising from mesenchymal cells (MESODERM) except those of smooth muscle cells (LEIOMYOMA) or Schwann cells (SCHWANNOMA).Goiter: Enlargement of the THYROID GLAND that may increase from about 20 grams to hundreds of grams in human adults. Goiter is observed in individuals with normal thyroid function (euthyroidism), thyroid deficiency (HYPOTHYROIDISM), or hormone overproduction (HYPERTHYROIDISM). Goiter may be congenital or acquired, sporadic or endemic (GOITER, ENDEMIC).Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.