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
Well differentiated fetal adenocarcinoma of lung
A well-differentiated fetal adenocarcinoma (WDFA) of lung is a rare low grade lung tumor. Some consider this as a variant of adenocarcinoma with others considering this under the group of pulmonary blastomas 5.
According to classification by the World Health Organization in 1999, it was remove...
Article
Quadruple screening test
The quadruple screening test, also known as the quad screen, AFP Plus quad test or multiple marker screening test, is a maternal antenatal screening blood test that can be used in conjunction with other investigations e.g. ultrasound soft markers, to estimate the risk of aneuploidy 1.
This is ...
Article
Homer Wright rosettes
Homer Wright rosettes are differentiated tumor cells grouped around a central region containing neuropil (therefore its association with tumors of neuronal origin).
Pathology
Examples of tumors where these can be seen include:
medulloblastoma (the presence of Homer Wright rosettes in a poster...
Article
Ependymal rosettes (ependymoma)
Ependymal rosettes correspond to a histologic architectural pattern that are characteristic of ependymomas, as tumor cells form structures similar to the lining of normal ventricles. They are characterized by a halo or spoke-wheel arrangement of tumor cells surrounding an empty central tubule lu...
Article
Prostate specific antigen
Prostate specific antigen (PSA) is used as a tumor marker for prostate cancer.
PSA is a 33-kilodalton glycoprotein produced in prostate epithelial cells. Its normal physiologic role is as a liquefying agent for seminal fluid; only a tiny amount leaks into the blood, so its normal serum level is...
Article
Primary pulmonary enteric adenocarcinoma
Pulmonary enteric adenocarcinoma (PEAC) or pulmonary adenocarcinoma with enteric differentiation (PAED) is an extremely rare variant of primary invasive adenocarcinoma of the lung. It has morphological and immunohistochemical profiles overlapping with that of colorectal carcinoma. Due to this, i...
Article
Beryllium
Beryllium (chemical symbol Be) is an alkaline earth metallic element, that has no known function in any organism. Unfortunately beryllium is very poisonous, manifesting as chronic beryllium lung disease, which causes premature mortality in one third 1.
Chemistry
Basic chemistry
Beryllium is a...
Article
Atrophy
Atrophy is a reduction in the size of an organ/tissue. Microscopically this is a reduction in cell size/volume caused by a reduction in protein synthesis and/or increased protein degradation 1.
Atrophy may be physiologic or pathological.
Physiological atrophy is commonly seen in the normal dev...
Article
HER-2 mutations in lung cancer
Human epidermal growth factor receptor 2 (HER-2) mutations may be detected in approximately 3% of lung adenocarcinomas 1.
Radiographic features
CT
Early studies have suggested HER2-mutant tumors exhibit more aggressive features in general and tend to:
exhibit a locally-invasive behavior comp...
Article
Opportunistic infection
Opportunistic infections (OI) are caused by micro-organisms (sometimes called opportunists) that under normal circumstances do not cause infections, but in certain clinical contexts, most commonly immunosuppression, may become pathogenic 1.
Article
Immunity
The human body regularly encounters harmful micro-organisms, and because of this it has developed a system of defenses to help identify and eliminate infective pathogens in the body, known as immunity, executed by the immune system. This system also contributes to antioncogenic mechanisms.
Type...
Article
Vector (infectious disease)
A vector, (also known as a biological vector) in the context of infectious diseases, is a carrier, in particular an animal, and most commonly an arthropod, that transmits the infective entity from one host to another 1. Often the infective agent undergoes some change as part of its normal life c...
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 ...
Article
Eburnation
Eburnation describes the appearance of bone following a degenerative process in which subchondral or otherwise exposed bone acquires a non-anatomical sclerotic, microimpacted, and "polished" articular surface.
This phenomenon typically arises in one of two situations:
hypertrophic non-union of...
Article
Programmed death-ligand 1 (PD-L1)-targeted monoclonal antibodies
Programmed death-ligand 1 (PD-L1)-targeted monoclonal antibodies interact with a protein called PD-1 on T-cells and can be useful in determining if certain immunomodulation therapies can be used in treatment of certain types of cancers. PD-L1 is a major immune checkpoint protein that mediates an...
Article
Vascular invasion in lung cancer
Vascular invasion in lung cancer is one of the invasive patterns that can occur in lung cancer. Dependent on the publication, this could mean:
intratumoral vascular invasion (IVI)
microscopic vascular invasion (MVI)
lymphovascular invasion (LVI)
lymphatic permeation
arterial invasion
veno...
Article
Congestion
Congestion is a pathological term referring to reduced blood flow out from tissues, which may be localized or systemic 1.
Clinical presentation
Congestion commonly presents with increased swelling and edema of tissues where blood flow is reduced. With prolonged congestion, the tissues may beco...
Article
Neuritic plaques
Neuritic plaques (also known as senile plaques) are pathological extracellular aggregates formed around a core of amyloid β peptide and are a hallmark of Alzheimer disease.
They should not be confused with neurofibrillary tangles which are intracytoplasmic.
Pathology
Neuritic plaques are ext...
Article
Endemic
The epidemiological term endemic is used for any condition that persists within a particular community/locale without the need for external input of new disease, i.e. the disease in question has attained a steady-state in the affected population 1. For this to happen the basic reproductive numbe...
Article
Cobalt
Cobalt (chemical symbol Co) is an essential trace element. Its most important function in humans is as the active metal atomic center of vitamin B12.
Chemistry
Basic chemistry
Cobalt is a shiny grey-silvery transition metal with an atomic number 27 and an atomic weight of 58.93 Daltons (Da). ...
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