Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.

More than 200 results
Article

Precalcaneal congenital fibrolipomatous hamartoma

Precalcaneal congenital fibrolipomatous hamartoma (PCFH) is a rare, benign condition characterized by the presence of asymptomatic, skin-colored, unilateral or bilateral nodules in the medial precalcaneal plantar region of the heel. It is usually first seen within the first months of life, altho...
Article

Michaelis-Gutmann bodies

Michaeliis-Gutmann bodies are a histological feature characteristic of malakoplakia, typically seen in mid-stage disease 1,2. They are 1–10 μm laminated or targetoid basophilic focal inclusions of iron and calcium salts seen on light microscopy. They are also periodic acid–Schiff, and diastase-...
Article

Lipoma

Lipomas are benign tumors composed of mature adipocytes. They are the most common soft tissue tumor, seen in ~2% of the population.  Epidemiology Patients typically present in adulthood (5th-7th decades). Associations In some cases, multiple lipomas are associated with syndromes and other di...
Article

Birbeck granules

Birbeck granules refer to unusual rod-shaped structures specific to Langerhans cells. Their origin and function remain undetermined. Langerin is a crucial component within Birbeck granules. History and etymology Birbeck granules were first described by Michael S Birbeck in 1961 3. Related pat...
Article

Astrocytes

Astrocytes are cells of the central nervous system which act as both physical and physiological support for the neurons that are embedded between them, regulating water movement, facilitating metabolic exchange between neurons and capillaries, as well as responding to mechanical and biochemical ...
Article

Marjolin ulcer

Marjolin ulcers reflect malignant degeneration within pre-existing scars or areas of chronic inflammation such as burns or venous ulcers. Epidemiology Incidence is around 1-2% from all burn scars 1,2. The average latency period between initial injury to malignant transformation is 30-35 years....
Article

Grocott-Gomori methenamine silver stain

Grocott-Gomori methenamine silver (GMS) stain is a histological stain frequently used to screen specimens for fungal organisms. The procedure relies on the presence of polysaccharides along the fungal cell wall. During the staining process, chromic acid is first applied to the specimen which ox...
Article

Estimated glomerular filtration rate

The estimated glomerular filtration rate (eGFR) is widely used as a surrogate marker of renal function and is mathematically derived from the patient's serum creatinine, using their age, sex and ethnicity. There is some controversy over whether ethnicity should be included in the calculations. ...
Article

Sinonasal polyposis

Sinonasal polyposis refers to the presence of multiple benign polyps in the nasal cavity and paranasal sinuses. Epidemiology Sinonasal polyposis is most commonly encountered in adults and rare in children. Polyps are the most common expansile lesions of the nasal cavity 8. Associations Condi...
Article

Immunosuppression

Immunosuppression is the impairment of the body's immune system which can alter the ability of the body's defense mechanisms to prevent diseases, particularly certain infections, including opportunistic infections, and cancers.  Terminology Patients with immunosuppression are said to be immuno...
Article

Gain of function

Gain of function represents the set of laboratory techniques thanks to which it is possible to genetically modify a pathogen (for example a virus) in order to provide it with new capabilities.The field of application of the gain-of-function, in fact, is virology, in order to improve the understa...
Article

Polyostotic

Polyostotic, less commonly polystotic, is a term used to describe a condition involving multiple bones. Examples of conditions that can be polyostotic include Paget disease of the bone, fibrous dysplasia and melorheostosis. See also monostotic monomelic
Article

Monostotic

Monostotic is typically used to refer to a condition that involves only one bone. Examples of conditions that can be monostotic include fibrous dysplasia and melorheostosis. See also polyostotic monomelic
Article

DNA

DNA (deoxyribonucleic acid) is a nucleic acid that encodes the genetic information (genome) necessary for RNA (ribonucleic acid) transcription (transcriptome) and protein synthesis (proteome) 1. It is contained in the nucleus of eukaryotic cells in the form of chromatin or chromosomes 7,8. Mole...
Article

Pseudocyst

A pseudocyst is an abnormal fluid-filled cavity which is not lined by epithelium.  It is this fact that distinguishes it pathologically from a cyst, which is lined by epithelium. Examples of pseudocysts include: adrenal pseudocyst auricular pseudocyst intraspinal epidural gas pseudocysts me...
Article

Proteins

Proteins comprise long chains of amino acids joined together by peptide bonds. Structure A peptide bond is formed by the carboxyl group of one amino acid linking to the amino group of the next one.  Arbitrarily proteins are categorized according to length of the amino acid chain: if less than...
Article

Amino acids

Amino acids are the monomeric building blocks of proteins. Amino acids concatenate into chains, which are arbitrarily divided into peptides, polypeptides, or proteins according to chain length. Generally, chains of 10 or fewer amino acids are deemed to be peptides, chain length from 10-100 are p...
Article

RNA

RNA (ribonucleic acid) is one of the two major nucleic acids in biological cells, the other being DNA; unlike DNA, RNA is single-stranded. The composition of the nucleotides and nucleosides is also partly different due to variations in the monosaccharide and base constituents: D-ribose sugar rep...
Article

Alzheimer type II glia

Alzheimer type II glia are a type of glial cell. They are a pathological reactive astrocyte seen in the brain, unrelated to Alzheimer disease. They are seen most frequently in Wilson disease, but also in other systemic metabolic disorders, particularly those with elevated ammonia levels, typical...
Article

EGFR mutation

An epidermal growth factor receptor (EGFR) mutation may be expressed in a large proportion of non-small cell lung carcinomas (NSCLC). However, certain subtypes such as invasive mucinous adenocarcinoma of the lung can have very low expression. The presence of this mutation can be assessed on bio...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.