Carcinoma, Mucoepidermoid: A tumor of both low- and high-grade malignancy. The low-grade grow slowly, appear in any age group, and are readily cured by excision. The high-grade behave aggressively, widely infiltrate the salivary gland and produce lymph node and distant metastases. Mucoepidermoid carcinomas account for about 21% of the malignant tumors of the parotid gland and 10% of the sublingual gland. They are the most common malignant tumor of the parotid. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p575; Holland et al., Cancer Medicine, 3d ed, p1240)Salivary Gland Neoplasms: Tumors or cancer of the SALIVARY GLANDS.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)Salivary Glands, Minor: Accessory salivary glands located in the lip, cheek, tongue, floor of mouth, palate and intramaxillary.Parotid Neoplasms: Tumors or cancer of the PAROTID GLAND.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.Mucoepidermoid Tumor: A malignant epithelial tumor of glandular tissue, especially the salivary glands, characterized by acini with mucus-producing cells and by the presence of malignant squamous elements. Most mucoepidermoid tumors are low-grade lesions readily cured by adequate excision. They may appear in any age group. They grow slowly. If high-grade, they behave aggressively, widely infiltrating the salivary gland and producing lymph node and distant metastases. (Dorland, 27th ed; from DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p575)Carcinoma, 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)Tracheal NeoplasmsAdenoma, 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)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)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)Carcinoma, Hepatocellular: A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.Cystadenoma, Papillary: A benign neoplasm of the ovary.Maxillary Neoplasms: Cancer or tumors of the MAXILLA or upper jaw.Bronchial Neoplasms: Tumors or cancer of the BRONCHI.Palatal Neoplasms: Tumors or cancer of the PALATE, including those of the hard palate, soft palate and UVULA.Jaw Cysts: Saccular lesions lined with epithelium and contained within pathologically formed cavities in the jaw; also nonepithelial cysts (pseudocysts) as they apply to the jaw, e.g., traumatic or solitary cyst, static bone cavity, and aneurysmal bone cyst. True jaw cysts are classified as odontogenic or nonodontogenic.Sublingual Gland Neoplasms: Neoplasms of the sublingual glands.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.Mandibular Neoplasms: Tumors or cancer of the MANDIBLE.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.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.Lacrimal Apparatus Diseases: Diseases of the lacrimal apparatus.Gene Fusion: The GENETIC RECOMBINATION of the parts of two or more GENES resulting in a gene with different or additional regulatory regions, or a new chimeric gene product. ONCOGENE FUSION includes an ONCOGENE as at least one of the fusion partners and such gene fusions are often detected in neoplastic cells and are transcribed into ONCOGENE FUSION PROTEINS. ARTIFICIAL GENE FUSION is carried out in vitro by RECOMBINANT DNA technology.Maxillary Sinus: The air space located in the body of the MAXILLARY BONE near each cheek. Each maxillary sinus communicates with the middle passage (meatus) of the NASAL CAVITY on the same side.Radiography, Panoramic: Extraoral body-section radiography depicting an entire maxilla, or both maxilla and mandible, on a single film.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)Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Lung Neoplasms: Tumors or cancer of the LUNG.Liver Neoplasms: Tumors or cancer of the LIVER.Mouth Neoplasms: Tumors or cancer of the MOUTH.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.Oncogene Proteins, Fusion: The GENETIC TRANSLATION products of the fusion between an ONCOGENE and another gene. The latter may be of viral or cellular origin.Sclerosis: A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve.Carcinoma, Ductal, Breast: An invasive (infiltrating) CARCINOMA of the mammary ductal system (MAMMARY GLANDS) in the human BREAST.Carcinoma, Basal Cell: A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)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.