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.
320 results found
Article
Metaplasia
Metaplasia is a general pathology term that refers to the process when one cell type is replaced by another. It usually occurs in the context of a changed cellular environment to which the new cell type is better adapted 1.
Examples include 2-5:
Barrett esophagus: normal squamous epithelium re...
Article
DNA-methylation
DNA-methylation is an epigenetic modification of DNA by the addition of methyl groups (-CH3) which in turn results in changes to numerous processes including how genes are expressed.
The specific pattern of methylation is specific to different tissues, can change over time depending on physiol...
Article
Perianal genital warts
Perianal genital warts, also known as condyloma acuminata (singular: condyloma acuminatum), are a complication of human papillomavirus (HPV) infection. They are diagnosed clinically and are usually painless and benign, but can rarely undergo malignant transformation into squamous cell carcinoma....
Article
Nitrogen
Nitrogen (chemical symbol N) is one of the basic organic elements and is a key constituent of amino acids, the building blocks of proteins, and of nucleic acids (i.e. DNA and RNA). On earth it is the most abundant element found in its pure form and comprises 78% of all breathable air.
Chemistr...
Article
John Cunningham virus
John Cunningham virus, also known as human polyomavirus 2, universally known as the JC virus, is a ubiquitous double-stranded DNA virus of the polyomaviridae family 1. In immunocompromised individuals, reactivation can lead to a variety of disease of the central nervous system, the most common o...
Article
Alpha-fetoprotein
Alpha-fetoprotein (AFP) is an important plasma protein synthesized by the yolk sac and fetal liver. In adults, its main utility is as a tumor marker, primarily for hepatocellular carcinoma or teratoma. Functionally it is the fetal homologue of albumin, i.e. it acts as a major carrier protein in ...
Article
Manganese
Manganese (chemical symbol Mn) is one of the essential trace elements. It has an important biological role in the synthetic pathway for mucopolysaccharides, and it also is a cofactor for several enzymes.
Chemistry
Basic chemistry
Manganese has the atomic number 25 with an atomic weight of 54....
Article
Cystitis
Cystitis refers to inflammation of the urinary bladder. It may occur in isolation or be associated with inflammation of other parts of the urinary tract such as ureteritis or pyelonephritis.
Epidemiology
Cystitis is more common in females due to the short length of the urethra and its close pr...
Article
Verocay bodies
Verocay bodies are a histological feature of schwannomas and represent a particular growth pattern of Antoni type A pattern. A Verocay body is composed of two parallel rows of nuclear palisades separated by an anuclear zone 1.
History and etymology
Verocay bodies are named after Jose Juan Ver...
Article
CA 19-9
CA 19-9 (carbohydrate antigen 19-9 or cancer antigen 19-9) is a serum antigen (monosialoganglioside) that has increased diagnostic use in the management of several malignancies, mainly of hepatopancreaticobiliary origin. It is non-specific, however, and can rise in both malignant and non-maligna...
Article
C-reactive protein
C-reactive protein (CRP) is an acute phase reactant commonly measured in clinical practice as a marker of inflammation and to monitor disease severity, disease course and treatment response. It should not be confused with protein C (an anticoagulant) or C-peptide (a component of proinsulin).
Ph...
Article
Gene expression classifier
A gene expression classifier (GEC) test is a developing technology in the analysis of indeterminate thyroid nodules, using cells from a fine needle aspiration. The most common commercially available GEC in the United States is known as AFIRMA.
The test is designed to use molecular markers to he...
Article
Cell block cytology
Cell block cytology is a technique used in cytopathology (in addition to smears) for evaluation of tissue from fine needle aspirations (FNA) or fluid aspirations.
Multiple different protocols exist for processing a cell block, but the fundamental principles are the same:
fragmentary bits of ti...
Article
Von Brunn nests of the bladder
Von Brunn nests are non-neoplastic reactive urothelial lesions that occur in the bladder. They represent clusters of urothelial cells found in the superficial lamina propria resulting from the invagination of the superficial urothelium.
Histologically, those nests generally show uniform size a...
Article
Hamartoma
A hamartoma (plural: hamartomas or hamartomata) is a benign tumor-like malformation that consists of a collection of architecturally disorganized cells located in an area of the body where the cells are normally found. It is often due to abnormal development.
In radiology, hamartomas often mimi...
Article
Arias-Stella reaction
An Arias-Stella reaction is a common gynecological histological finding in curettage specimens of gestational endometrium describing a non-neoplastic lesion that is easily confused with uterine malignancy 1,2.
Pathology
An Arias-Stella reaction is due to hormonal hyperstimulation causing atypi...
Article
Fistula
A fistula (plural: fistulae or fistulas) is an abnormal connection between two epithelial surfaces such as between hollow organs, skin or vessels. Conventionally, the name of a specific fistula type is a combination of the two organs. For discussions of specific fistulae please refer to individu...
Article
Mycobacterium tuberculosis
Mycobacterium tuberculosis is a thin, slightly curved bacillus. A member of the Mycobacterium tuberculosis complex, it is an obligate aerobic bacterium that is the etiologic agent of the majority of tuberculosis cases.
Epidemiology
The worldwide incidence of tuberculosis was 8.7 million in 20...
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
mTOR protein
The mTOR proteins, an abbreviation for mammalian target of rapamycin, also known as mechanistic target of rapamycin, are two proteins that are involved in cell signaling pathways implicated in tumorigenesis.
The mTOR proteins are serine/threonine protein kinases that combine with several other ...
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