Paraffin: A mixture of solid hydrocarbons obtained from petroleum. It has a wide range of uses including as a stiffening agent in ointments, as a lubricant, and as a topical anti-inflammatory. It is also commonly used as an embedding material in histology.Paraffin Embedding: The infiltrating of tissue specimens with paraffin, as a supporting substance, to prepare for sectioning with a microtome.Tissue 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.Formaldehyde: A highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717)Fixatives: Agents employed in the preparation of histologic or pathologic specimens for the purpose of maintaining the existing form and structure of all of the constituent elements. Great numbers of different agents are used; some are also decalcifying and hardening agents. They must quickly kill and coagulate living tissue.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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Frozen Sections: Thinly cut sections of frozen tissue specimens prepared with a cryostat or freezing microtome.Microtomy: The technique of using a microtome to cut thin or ultrathin sections of tissues embedded in a supporting substance. The microtome is an instrument that hold a steel, glass or diamond knife in clamps at an angle to the blocks of prepared tissues, which it cuts in sections of equal thickness.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.Kerosene: A refined petroleum fraction used as a fuel as well as a solvent.Waxes: A plastic substance deposited by insects or obtained from plants. Waxes are esters of various fatty acids with higher, usually monohydric alcohols. The wax of pharmacy is principally yellow wax (beeswax), the material of which honeycomb is made. It consists chiefly of cerotic acid and myricin and is used in making ointments, cerates, etc. (Dorland, 27th ed)Tissue Preservation: The process by which a tissue or aggregate of cells is kept alive outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Plastic Embedding: The infiltrating of histological specimens with plastics, including acrylic resins, epoxy resins and polyethylene glycol, for support of the tissues in preparation for sectioning with a microtome.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.Mineral Oil: A mixture of liquid hydrocarbons obtained from petroleum. It is used as laxative, lubricant, ointment base, and emollient.Tissue Embedding: The technique of placing cells or tissue in a supporting medium so that thin sections can be cut using a microtome. The medium can be paraffin wax (PARAFFIN EMBEDDING) or plastics (PLASTIC EMBEDDING) such as epoxy resins.Decalcification Technique: Removal of minerals from bones during bone examination.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.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.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Hematoxylin: A dye obtained from the heartwood of logwood (Haematoxylon campechianum Linn., Leguminosae) used as a stain in microscopy and in the manufacture of ink.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Nucleolus Organizer Region: The chromosome region which is active in nucleolus formation and which functions in the synthesis of ribosomal RNA.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Pneumonia, Lipid: Pneumonia due to aspiration or inhalation of various oily or fatty substances.Oils: Unctuous combustible substances that are liquid or easily liquefiable on warming, and are soluble in ether but insoluble in water. Such substances, depending on their origin, are classified as animal, mineral, or vegetable oils. Depending on their behavior on heating, they are volatile or fixed. (Dorland, 28th ed)DNA, Neoplasm: DNA present in neoplastic tissue.Ki-67 Antigen: A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.Histocytochemistry: Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.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.Palatine Tonsil: A round-to-oval mass of lymphoid tissue embedded in the lateral wall of the PHARYNX. There is one on each side of the oropharynx in the fauces between the anterior and posterior pillars of the SOFT PALATE.Eosine Yellowish-(YS): A versatile red dye used in cosmetics, pharmaceuticals, textiles, etc., and as tissue stain, vital stain, and counterstain with HEMATOXYLIN. It is also used in special culture media.Breast Neoplasms: Tumors or cancer of the human BREAST.Pathology, Molecular: A subspecialty of pathology concerned with the molecular basis (e.g., mutations) of various diseases.Silver Staining: The use of silver, usually silver nitrate, as a reagent for producing contrast or coloration in tissue specimens.Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Ploidies: The degree of replication of the chromosome set in the karyotype.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.Tissue Array Analysis: The simultaneous analysis of multiple samples of TISSUES or CELLS from BIOPSY or in vitro culture that have been arranged in an array format on slides or microchips.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.Tissue Banks: Centers for acquiring, characterizing, and storing organs or tissue for future use.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.Proliferating Cell Nuclear Antigen: Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.Adenofibroma: A benign neoplasm composed of glandular and fibrous tissues, with a relatively large proportion of glands. (Stedman, 25th ed)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)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)Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Digoxigenin: 3 beta,12 beta,14-Trihydroxy-5 beta-card-20(22)-enolide. A cardenolide which is the aglycon of digoxin. Can be obtained by hydrolysis of digoxin or from Digitalis orientalis L. and Digitalis lanata Ehrh.Periodic Acid-Schiff Reaction: A histochemical technique for staining carbohydrates. It is based on PERIODIC ACID oxidation of a substance containing adjacent hydroxyl groups. The resulting aldehydes react with Schiff reagent to form a colored product.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.Emulsions: Colloids formed by the combination of two immiscible liquids such as oil and water. Lipid-in-water emulsions are usually liquid, like milk or lotion. Water-in-lipid emulsions tend to be creams. The formation of emulsions may be aided by amphiphatic molecules that surround one component of the system to form MICELLES.Diathermy: The induction of local hyperthermia by either short radio waves or high-frequency sound waves.Histology: The study of the structure of various TISSUES of organisms on a microscopic level.DNA Probes, HPV: DNA probes specific for the identification of human papilloma virus.Receptors, Estrogen: Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.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.Keratin-13: A type I keratin that is found associated with the KERATIN-4 in the internal stratified EPITHELIUM. Defects in gene for keratin 13 cause HEREDITARY MUCOSAL LEUKOKERATOSIS.Lymphoma, T-Cell: A group of heterogeneous lymphoid tumors representing malignant transformations of T-lymphocytes.Carcinoma, Ductal, Breast: An invasive (infiltrating) CARCINOMA of the mammary ductal system (MAMMARY GLANDS) in the human BREAST.