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Schwannomas
A schwannoma (or neurilemmoma) is a usually benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves. Schwannomas are homogeneous tumors, consisting only of Schwann cells. The tumor cells always stay on the outside of the nerve, but the tumor itself may either push the nerve aside and/or up against a bony structure (thereby possibly causing damage). Schwannomas are relatively slow-growing. For reasons not yet understood, schwannomas are mostly benign and less than 1% become malignant, degenerating into a form of cancer known as neurofibrosarcoma. These masses are generally contained within a capsule, so surgical removal is often successful. Schwannomas can be associated with neurofibromatosis type II, which may be due to a loss-of-function mutation in the protein merlin. They are universally S-100 positive, which is a marker for cells of neural crest cell origin. Schwannomas of the head and neck are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibular Schwannoma
A vestibular schwannoma (VS), also called acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve that passes from the inner ear to the brain. The tumor originates when Schwann cells that form the insulating myelin sheath on the nerve malfunction. Normally, Schwann cells function beneficially to protect the nerves which transmit balance and sound information to the brain. However, sometimes a mutation in the tumor suppressor gene, NF2, located on chromosome 22, results in abnormal production of the cell protein named ''Merlin'', and Schwann cells multiply to form a tumor. The tumor originates mostly on the vestibular division of the nerve rather than the cochlear division, but hearing as well as balance will be affected as the tumor enlarges. The great majority of these VSs (95%) are unilateral, in one ear only. They are called "sporadic" (i.e., by-chance, non-hereditary). Although non-cancerous, they can do harm or even become life-threatening if they gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofibromatosis Type II
Neurofibromatosis type II (also known as MISME syndrome – multiple inherited schwannomas, meningiomas, and ependymomas) is a genetic condition that may be inherited or may arise spontaneously, and causes benign tumors of the brain, spinal cord, and peripheral nerves. The types of tumors frequently associated with NF2 include vestibular schwannomas, meningiomas, and ependymomas. The main manifestation of the condition is the development of bilateral benign brain tumors in the nerve sheath of the cranial nerve VIII, which is the "auditory-vestibular nerve" that transmits sensory information from the inner ear to the brain. Besides, other benign brain and spinal tumors occur. Symptoms depend on the presence, localisation and growth of the tumor(s). Many people with this condition also experience vision problems. Neurofibromatosis type II (NF2 ''or'' NF II) is caused by mutations of the "Merlin" gene, which seems to influence the form and movement of cells. The principal treatments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Sheath Tumor
A nerve sheath tumor is a type of tumor of the nervous system ( nervous system neoplasm) which is made up primarily of the myelin surrounding nerves. Nerve sheath tumors can be benign or malignant, and may affect both the peripheral and central nervous systems. There are three main types of nerve sheath tumors: schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors. Classification of nerve sheath tumors Spinal nerve sheath tumors Spinal nerve sheath tumors are typically intradural, meaning that they arise inside the dura mater surrounding the spinal cord (thecal sac), but may also be found in other areas of the spine. Spinal nerve sheath tumors generally arise as single lesions. Presence of multiple lesions is associated with genetic conditions including neurofibromatosis type 1, neurofibromatosis type 2, and Schwannomatosis. Most spinal schwannomas are intradural-extramedullary, growing inside the thecal sac, but outside the spinal cord itself. Intradura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palisaded Encapsulated Neuroma
Palisaded encapsulated neuroma (PEN) is a rare, benign cutaneous condition characterized by small, firm, non-pigmented nodules or papules. They typically occur as a solitary (single) lesion near the mucocutaneous junction of the skin of the face, although they can occur elsewhere on the body. Symptoms PEN tumours are always painless, solid masses felt on the skin that, due to their slow-growing nature, typically take many years to grow to a size where they are noticeable. There are never any symptoms associated with systemic disease. Diagnosis As mentioned previously, PEN is a benign, firm, flesh-coloured lesion that typically occurs in dermis of the skin of the face. The lesions are typically between 2–6mm and are slow-growing. On the face, the lesions can be found on the eyelid, nose and in the oral mucosa, however, the lesions can also occur on the shoulder, arm, hand, foot and the glans of the penis. PEN is diagnosed by clinical recognition of the lesion and on subseq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-100 Protein
The S100 proteins are a family of low molecular-weight proteins found in vertebrates characterized by two calcium-binding sites that have helix-loop-helix ("EF-hand-type") conformation. At least 21 different S100 proteins are known. They are encoded by a family of genes whose symbols use the ''S100'' prefix, for example, ''S100A1'', ''S100A2'', ''S100A3''. They are also considered as damage-associated molecular pattern molecules (DAMPs), and knockdown of aryl hydrocarbon receptor downregulates the expression of S100 proteins in THP-1 cells. Structure Most S100 proteins consist of two identical polypeptides (homodimeric), which are held together by noncovalent bonds. They are structurally similar to calmodulin. They differ from calmodulin, though, on the other features. For instance, their expression pattern is cell-specific, i.e. they are expressed in particular cell types. Their expression depends on environmental factors. In contrast, calmodulin is a ubiquitous and universa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuro-oncology
Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are (at least eventually) very dangerous and life-threatening (astrocytoma, glioma, glioblastoma multiforme, ependymoma, pontine glioma, and brain stem tumors are among the many examples of these). Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade (highly anaplastic) astrocytoma/oligodendroglioma are among the worst. In these cases, untreated survival usually amounts to only a few months, and survival with current radiation and chemotherapy treatments may extend that time from around a year to a year and a half, possibly two or more, depending on the patient's condition, immune function, treatments used, and the specific type of malignant brain neoplasm. Surgery may in some cases be curative, but, as a general rule, malignant brain cancers tend to regenerate and emerge from remission easily, especially highly malignant cases. In such cases, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurofibroma
A neurofibroma is a benign nerve-sheath tumor in the peripheral nervous system. In 90% of cases, they are found as stand-alone tumors (solitary neurofibroma, solitary nerve sheath tumor or sporadic neurofibroma), while the remainder are found in persons with neurofibromatosis type I (NF1), an autosomal-dominant genetically inherited disease. They can result in a range of symptoms from physical disfiguration and pain to cognitive disability. Neurofibromas arise from nonmyelinating-type Schwann cells that exhibit biallelic inactivation of the ''NF1'' gene that codes for the protein neurofibromin. This protein is responsible for regulating the RAS-mediated cell growth signaling pathway. In contrast to schwannomas, another type of tumor arising from Schwann cells, neurofibromas incorporate many additional types of cells and structural elements in addition to Schwann cells, making it difficult to identify and understand all the mechanisms through which they originate and develop. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verocay Bodies
Verocay bodies were first described by Uruguayan neuro-pathologist José Juan Verocay in 1910. It is a required histopathology, histopathological finding for diagnosing schwannomas (tumors of Schwann cells). Verocay bodies are a component of "Antoni A" which are the dense areas of schwannomas located between Palisade (pathology), palisading Von Economo neuron, spindle cells found in neoplasms. Two nuclear palisading regions and an anuclear zone make up one Verocay body. Originally Verocay bodies were called 'neuromas', a term coined by Louis Odier in 1803. The name changed to ‘neuro-fibroma’ under Friedrich Daniel von Recklinghausen, Von Recklinghausen and later in 1935 to ‘neurilemmomas’ under Arthur Purdy Stout. When Harkin and Reed coined the term 'schwannoma' in 1968, Verocay bodies received their present-day name. Features on histopathological examination include: 1. Eosinophilic acellular area due to overexpression of lamins. 2. Consisting of reduplicated baseme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verocay Body
Verocay bodies were first described by Uruguayan neuro-pathologist José Juan Verocay in 1910. It is a required histopathological finding for diagnosing schwannomas (tumors of Schwann cells). Verocay bodies are a component of "Antoni A" which are the dense areas of schwannomas located between palisading spindle cells found in neoplasms. Two nuclear palisading regions and an anuclear zone make up one Verocay body. Originally Verocay bodies were called 'neuromas', a term coined by Louis Odier in 1803. The name changed to ‘neuro-fibroma’ under Von Recklinghausen and later in 1935 to ‘neurilemmomas’ under Arthur Purdy Stout. When Harkin and Reed coined the term 'schwannoma' in 1968, Verocay bodies received their present-day name. Features on histopathological examination include: 1. Eosinophilic acellular area due to overexpression of lamins. 2. Consisting of reduplicated basement membrane The basement membrane, also known as base membrane, is a thin, pliable shee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrograph
A micrograph is an image, captured photographically or digitally, taken through a microscope or similar device to show a magnify, magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a microscope but is only slightly magnified, usually less than 10 times. Micrography is the practice or art of using microscopes to make photographs. A photographic micrograph is a photomicrograph, and one taken with an electron microscope is an electron micrograph. A micrograph contains extensive details of microstructure. A wealth of information can be obtained from a simple micrograph like behavior of the material under different conditions, the phases found in the system, failure analysis, grain size estimation, elemental analysis and so on. Micrographs are widely used in all fields of microscopy. Types Photomicrograph A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, a process referred to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tinnitus
Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely quiet room; but this is of concern only if it is bothersome, interferes with normal hearing, or is associated with other problems. The word ''tinnitus'' comes from the Latin language, Latin ''wikt:en:tinnitus#Latin, tinnire'', "to ring." In some people, it interferes with concentration, and can be associated with anxiety and Depression (mood), depression. Tinnitus is usually associated with hearing loss and decreased comprehension of speech in noisy environments. It is common, affecting about 10–15% of people. Most tolerate it well, and it is a significant (severe) problem in only 1–2% of people. It can trigger a fight-or-flight response, as the brain may perceive it as dangerous and important. Rather than a disease, tinnitus is a sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Inclusion Bodies That Aid In Diagnosis Of Cutaneous Conditions
Many skin conditions require a skin biopsy for confirmation of the diagnosis. With several of these conditions there are features within the cells contained in the skin biopsy specimen that have elements in their cytoplasm or nucleus that have a characteristic appearance unique to the condition. These elements are termed inclusion bodies. See also * List of contact allergens * List of cutaneous conditions * List of genes mutated in cutaneous conditions * List of target antigens in pemphigus * List of specialized glands within the human integumentary system This article contains a list of glands of the human body List of endocrine and exocrine glands Skin There are several specialized glands within the human integumentary system that are derived from apocrine or sebaceous gland precursors. There ... References * * {{DEFAULTSORT:Inclusion bodies that aid in diagnosis of cutaneous conditions Dermatology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
