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.Cyst Fluid: Liquid material found in epithelial-lined closed cavities or sacs.Ovarian Cysts: General term for CYSTS and cystic diseases of the OVARY.Epidermal Cyst: Intradermal or subcutaneous saclike structure, the wall of which is stratified epithelium containing keratohyalin granules.Mediastinal Cyst: Cysts of one of the parts of the mediastinum: the superior part, containing the trachea, esophagus, thoracic duct and thymus organs; the inferior middle part, containing the pericardium; the inferior anterior part containing some lymph nodes; and the inferior posterior part, containing the thoracic duct and esophagus.Synovial Cyst: Non-neoplastic tumor-like lesions at joints, developed from the SYNOVIAL MEMBRANE of a joint through the JOINT CAPSULE into the periarticular tissues. They are filled with SYNOVIAL FLUID with a smooth and translucent appearance. A synovial cyst can develop from any joint, but most commonly at the back of the knee, where it is known as POPLITEAL CYST.Bone Cysts: Benign unilocular lytic areas in the proximal end of a long bone with well defined and narrow endosteal margins. The cysts contain fluid and the cyst walls may contain some giant cells. Bone cysts usually occur in males between the ages 3-15 years.Bronchogenic Cyst: A usually spherical cyst, arising as an embryonic out-pouching of the foregut or trachea. It is generally found in the mediastinum or lung and is usually asymptomatic unless it becomes infected.Dermoid Cyst: A tumor consisting of displaced ectodermal structures along the lines of embryonic fusion, the wall being formed of epithelium-lined connective tissue, including skin appendages, and containing keratin, sebum, and hair. (Stedman, 25th ed)Odontogenic Cysts: Cysts found in the jaws and arising from epithelium involved in tooth formation. They include follicular cysts (e.g., primordial cyst, dentigerous cyst, multilocular cyst), lateral periodontal cysts, and radicular cysts. They may become keratinized (odontogenic keratocysts). Follicular cysts may give rise to ameloblastomas and, in rare cases, undergo malignant transformation.Radicular Cyst: Slow-growing fluid-filled epithelial sac at the apex of a tooth with a nonvital pulp or defective root canal filling.Dentigerous Cyst: Most common follicular odontogenic cyst. Occurs in relation to a partially erupted or unerupted tooth with at least the crown of the tooth to which the cyst is attached protruding into the cystic cavity. May give rise to an ameloblastoma and, in rare instances, undergo malignant transformation.Mesenteric Cyst: A rare intra-abdominal tumor in the MESENTERY. Mesenteric cysts are usually benign and can be very large fluid-filled (2000 mL) lesions.Bone Cysts, Aneurysmal: Fibrous blood-filled cyst in the bone. Although benign it can be destructive causing deformity and fractures.Tarlov Cysts: Perineurial cysts commonly found in the SACRAL REGION. They arise from the PERINEURIUM membrane within the SPINAL NERVE ROOTS. The distinctive feature of the cysts is the presence of spinal nerve root fibers within the cyst wall, or the cyst cavity itself.Popliteal Cyst: A SYNOVIAL CYST located in the back of the knee, in the popliteal space arising from the semimembranous bursa or the knee joint.Esophageal Cyst: Any fluid-filled closed cavity or sac (CYSTS) that is lined by an EPITHELIUM and found in the ESOPHAGUS region.Echinococcosis: An infection caused by the infestation of the larval form of tapeworms of the genus Echinococcus. The liver, lungs, and kidney are the most common areas of infestation.Urachal Cyst: Cyst occurring in a persistent portion of the urachus, presenting as an extraperitoneal mass in the umbilical region. It is characterized by abdominal pain, and fever if infected. It may rupture, leading to peritonitis, or it may drain through the umbilicus.Breast Cyst: A fluid-filled closed cavity or sac that is lined by an EPITHELIUM and found in the BREAST. It may appear as a single large cyst in one breast, multifocal, or bilateral in FIBROCYSTIC BREAST DISEASE.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.Giardia: A genus of flagellate intestinal EUKARYOTES parasitic in various vertebrates, including humans. Characteristics include the presence of four pairs of flagella arising from a complicated system of axonemes and cysts that are ellipsoidal to ovoidal in shape.Echinococcosis, Hepatic: Liver disease caused by infections with parasitic tapeworms of the genus ECHINOCOCCUS, such as Echinococcus granulosus or Echinococcus multilocularis. Ingested Echinococcus ova burrow into the intestinal mucosa. The larval migration to the liver via the PORTAL VEIN leads to watery vesicles (HYDATID CYST).Periodontal Cyst: An epithelium-lined sac containing fluid; usually found at the apex of a pulp-involved tooth. The lateral type occurs less frequently along the side of the root.Kidney Diseases, Cystic: A heterogeneous group of hereditary and acquired disorders in which the KIDNEY contains one or more CYSTS unilaterally or bilaterally (KIDNEY, CYSTIC).Thyroglossal Cyst: A cyst in the neck caused by persistence of portions of, or by lack of closure of, the primitive thyroglossal duct. (Dorland, 27th ed)Nonodontogenic Cysts: Cysts formed from epithelial inclusions in the lines of fusion of the embryonic processes which form the jaws. They include nasopalatine or incisive canal cyst, incisive papilla cyst, globulomaxillary cyst, median palatal cyst, median alveolar cyst, median mandibular cyst, and nasoalveolar cyst.Echinococcus granulosus: A species of hydatid tapeworm (class CESTODA) in the family Taeniidae, whose adult form infects the DIGESTIVE TRACT of DOGS, other canines, and CATS. The larval form infects SHEEP; PIGS; HORSES; and may infect humans, where it migrates to various organs and forms permanent HYDATID CYSTS.Maxillary DiseasesParovarian Cyst: A cyst (CYSTS) near the OVARY, derived from anomalies of the FALLOPIAN TUBES or the BROAD LIGAMENT. The paramesonephric type consists of ciliated cells similar to the oviduct epithelium. The mesonephric type consisted of an epithelium with minimally surface structures. They can be found on the thin oviduct (paratubal cysts) or near its fimbriated end (hydatid of Morgagni).Echinococcosis, Pulmonary: Helminth infection of the lung caused by Echinococcus granulosus or Echinococcus multilocularis.Anticestodal Agents: Agents used to treat tapeworm infestations in man or animals.Odontogenic Cyst, Calcifying: A mixed radiolucent-radiopaque lesion of the jaws with features of both a cyst and a solid neoplasm. It is characterized microscopically by an epithelial lining showing a palisaded layer of columnar basal cells, presence of ghost cell keratinization, dentinoid, and calcification. (Stedman, 25th ed)Mandibular DiseasesPolycystic Kidney, Autosomal Dominant: Kidney disorders with autosomal dominant inheritance and characterized by multiple CYSTS in both KIDNEYS with progressive deterioration of renal function.Albendazole: A benzimidazole broad-spectrum anthelmintic structurally related to MEBENDAZOLE that is effective against many diseases. (From Martindale, The Extra Pharmacopoeia, 30th ed, p38)Echinococcus: A genus of very small TAPEWORMS, in the family Taeniidae. The adult form is found in various CARNIVORA but not humans. The larval form is seen in humans under certain epidemiologic circumstances.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Giardia lamblia: A species of parasitic EUKARYOTES that attaches itself to the intestinal mucosa and feeds on mucous secretions. The organism is roughly pear-shaped and motility is somewhat erratic, with a slow oscillation about the long axis.Branchioma: A tumor derived from branchial epithelium or branchial rests. (Dorland, 27th ed)Splenic DiseasesGiardiasis: An infection of the SMALL INTESTINE caused by the flagellated protozoan GIARDIA LAMBLIA. It is spread via contaminated food and water and by direct person-to-person contact.Spores, Protozoan: A vegetative stage in the life cycle of sporozoan protozoa. It is characteristic of members of the phyla APICOMPLEXA and MICROSPORIDIA.Iris Diseases: Diseases, dysfunctions, or disorders of or located in the iris.TRPP Cation Channels: A subgroup of TRP cation channels that are widely expressed in various cell types. Defects are associated with POLYCYSTIC KIDNEY DISEASES.Brain Diseases: Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.Rupture, Spontaneous: Tear or break of an organ, vessel or other soft part of the body, occurring in the absence of external force.Liver Diseases: Pathological processes of the LIVER.Arachnoid: A delicate membrane enveloping the brain and spinal cord. It lies between the PIA MATER and the DURA MATER. It is separated from the pia mater by the subarachnoid cavity which is filled with CEREBROSPINAL FLUID.Mebendazole: A benzimidazole that acts by interfering with CARBOHYDRATE METABOLISM and inhibiting polymerization of MICROTUBULES.Curettage: A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. (From Stedman, 25th ed & Dorland, 27th ed)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.Suction: The removal of secretions, gas or fluid from hollow or tubular organs or cavities by means of a tube and a device that acts on negative pressure.Spinal DiseasesThird Ventricle: A narrow cleft inferior to the CORPUS CALLOSUM, within the DIENCEPHALON, between the paired thalami. Its floor is formed by the HYPOTHALAMUS, its anterior wall by the lamina terminalis, and its roof by EPENDYMA. It communicates with the FOURTH VENTRICLE by the CEREBRAL AQUEDUCT, and with the LATERAL VENTRICLES by the interventricular foramina.Cholangiopancreatography, Magnetic Resonance: Non-invasive diagnostic technique for visualizing the PANCREATIC DUCTS and BILE DUCTS without the use of injected CONTRAST MEDIA or x-ray. MRI scans provide excellent sensitivity for duct dilatation, biliary stricture, and intraductal abnormalities.Oocysts: Zygote-containing cysts of sporozoan protozoa. Further development in an oocyst produces small individual infective organisms called SPOROZOITES. Then, depending on the genus, the entire oocyst is called a sporocyst or the oocyst contains multiple sporocysts encapsulating the sporozoites.Nematoda: A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.Craniopharyngioma: A benign pituitary-region neoplasm that originates from Rathke's pouch. The two major histologic and clinical subtypes are adamantinous (or classical) craniopharyngioma and papillary craniopharyngioma. The adamantinous form presents in children and adolescents as an expanding cystic lesion in the pituitary region. The cystic cavity is filled with a black viscous substance and histologically the tumor is composed of adamantinomatous epithelium and areas of calcification and necrosis. Papillary craniopharyngiomas occur in adults, and histologically feature a squamous epithelium with papillations. (From Joynt, Clinical Neurology, 1998, Ch14, p50)Acanthamoeba: A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.