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Endolymphatic Sac Tumor
An endolymphatic sac tumor (ELST) is a very uncommon papillary epithelial neoplasm arising within the endolymphatic sac or endolymphatic duct. This tumor shows a very high association with Von Hippel–Lindau syndrome (VHL). Classification The ELST has been referred to as adenocarcinoma of endolymphatic sac, Heffner tumor, papillary adenomatous tumor, aggressive papillary adenoma, invasive papillary cystadenoma, and papillary tumor of temporal bone. However, these names are not encouraged as they do not accurately classify the current understanding of the tumor. Signs and symptoms Patients with ELST may present clinically with progressive or fluctuating, one sided sensorineural hearing loss which may mimick Ménière's disease due to the development of tumor associated endolymphatic hydrops. Patients may also experience tinnitus, vertigo, and loss of vestibular function (ataxia). Alternatively, symptom onset may be sudden, due to intralabyrinthine hemorrhage. Patients may also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post Contrast T1 Weighted MRI Demonstrates Intense Enhancement Of Both The Eye And The Endolymphatic Sac Tumor
Post or POST commonly refers to: *Mail, the postal system, especially in Commonwealth of Nations countries **An Post, the Irish national postal service **Canada Post, Canadian postal service **Deutsche Post, German postal service **Iraqi Post, Iraqi postal service ** Russian Post, Russian postal service **Hotel post, a service formerly offered by remote Swiss hotels for the carriage of mail to the nearest official post office **United States Postal Service or USPS ** Parcel post, a postal service for mail that is heavier than ordinary letters *Post, a job or occupation Post, POST, or posting may also refer to: Architecture and structures *Lamppost, a raised source of light on the edge of a road * Post (structural), timber framing *Post and lintel, a building system * Steel fence post *Trading post *Utility pole or utility post Military *Military base, an assigned station or a guard post ** Outpost (military), a military outpost **Guardpost, or guardhouse Geography *Post, Iran, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suppressor Gene
Epistasis is a phenomenon in genetics in which the effect of a gene mutation is dependent on the presence or absence of mutations in one or more other genes, respectively termed modifier genes. In other words, the effect of the mutation is dependent on the genetic background in which it appears. Epistatic mutations therefore have different effects on their own than when they occur together. Originally, the term ''epistasis'' specifically meant that the effect of a gene variant is masked by that of a different gene. The concept of ''epistasis'' originated in genetics in 1907 but is now used in biochemistry, computational biology and evolutionary biology. The phenomenon arises due to interactions, either between genes (such as mutations also being needed in regulators of gene expression) or within them (multiple mutations being needed before the gene loses function), leading to non-linear effects. Epistasis has a great influence on the shape of evolutionary landscapes, which le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Cranial Fossa
The posterior cranial fossa is part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum. This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. Anteriorly it extends to the apex of the petrous temporal. Posteriorly it is enclosed by the occipital bone. Laterally portions of the squamous temporal and mastoid part of the temporal bone form its walls. Features Foramen magnum The most conspicuous, large opening in the floor of the fossa. It transmits the medulla, the ascending portions of the spinal accessory nerve (XI), and the vertebral arteries. Internal acoustic meatus Lies in the anterior wall of the posterior cranial fossa. It transmits the facial (VII) and vestibulocochlear (VIII) cranial nerves into a canal in the petrous temporal bone. Jugular foramen Lies between the inferior edge of the petrous temporal bone and the adjacent occipital bone and transmits the internal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
