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.
23 results found
Article
Klebsiella
Klebsiella is a genus of Gram-negative, oxidase-negative, rod-shaped bacteria, which is relatively commonly encountered in the healthcare environment. It has numerous species, including K. pneumoniae, K. aerogenes, and K. rhinoscleromatis 1. Klebsiella may cause a range of infections, most commo...
Article
Sessile
Sessile is a pathological term which is used for lesions that are attached by their base, that is they lack a stalk i.e. are not pedunculated. It is most commonly used for intraluminal polyps in the GI tract.
History and etymology
Sessile is derived from the Latin word "sessilis" which means s...
Article
CA-125
CA-125 is a high-molecular-weight glycoprotein found on the surface of Müllerian and celomic epithelial-derived cell types and is the best-known tumor marker for epithelial ovarian cancer 6. Importantly, it may also be elevated in several other conditions (see differential diagnosis section belo...
Article
CEA
Serum CEA (carcinoembryonic antigen) is a cell-adhesive glycoprotein that was discovered in colorectal cancer in 1965, and is hence one of the oldest and most used tumor markers. Its name derives from its normal expression in fetoembryonic liver, gut and pancreas tissue.
Normal range of CEA is ...
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
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
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
Atresia
Atresia (plural: atresias) refers to a situation where there is absence, underdevelopment or abnormal closure, of a normal anatomical tubular structure or opening.
Contrast this with agenesis which refers to the complete absence of any anatomical structure including its primordial precursors.
...
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
KRAS mutation
KRAS (shortened name for the gene Kirsten RAt Sarcoma viral oncogene homolog) mutations are associated in a number of malignancies including:
certain adenocarcinomas of the lung
colorectal carcinoma 1
pancreatic ductal adenocarcinoma
Several germline KRAS mutations have also been found to b...
Article
Copper
Copper (chemical symbol Cu) is one of the trace elements. It has an important biological role as a redox agent and as a cofactor in cuproproteins, facilitating many vital metabolic reactions.
Chemistry
Basic chemistry
Copper is a transition metal with the atomic number 29 and an atomic weight...
Article
Serum ascites albumin gradient
The serum–ascites albumin gradient (SAAG) is the difference between the concurrently obtained serum albumin concentration and the albumin concentration of the ascitic fluid obtained during paracentesis.
Pathology
A difference ≥1.1 grams/deciliter (g/dL) indicates portal hypertension as the li...
Article
Liquefactive necrosis
Liquefactive necrosis is a form of necrosis where there is transformation of the tissue into a liquid viscous mass.
Pathology
In liquefactive necrosis, the affected cell is completely digested by hydrolytic enzymes leading to a soft, circumscribed lesion which can consist of fluid with remains...
Article
Amylase
Amylase is widely employed as a marker of acute pancreatitis and a significant elevation is diagnostic.
Physiology
α-amylase is a digestive enzyme that is predominantly secreted by the acinar cells of the exocrine pancreas. It is also secreted by the salivary glands. Pancreatic amylase is enco...
Article
Ascitic fluid cholesterol level
Ascitic fluid cholesterol level estimation is a simple and precise test for differentiating malignant ascites from non-malignant (cirrhotic) ascites 5-9.
Pathology
Ascites is the abnormal collection of fluid within the peritoneal cavity. Malignant ascites comprises ~10% and is usually seconda...
Article
Hernia (general)
Hernias (or herniae) are a common pathological entity, in which an anatomical structure passes into an abnormal location via an opening.
The opening may be a normal physiological aperture (e.g. hiatus hernia: stomach passes through the diaphragmatic esophageal hiatus) or pathological. Iatrogeni...
Article
Lamellated
The term lamellated (or laminated which means the same thing) is a radiopathological term used to describe the layered appearance of many calculi, including those of the renal tract, the salivary glands, and the biliary tree. The internal structure of these calculi has been likened to that of an...
Article
Hepatoblastoma histological classification
Although hepatoblastomas can be histologically classified into a variety of subtypes, it is important to remember that with the possible exception of small cell undifferentiated subtype, prognosis is independent of histology when adjusted for stage gender and age 1.
major categories
epithelial...
Article
Cyst
A cyst is an abnormal fluid-filled structure which is lined by epithelium; with one exception: lung cysts may contain gas or fluid. By contradistinction, a pseudocyst lacks an epithelial lining and instead has a vascular and fibrotic capsule.
Cysts are extremely common and found in most organs....
Article
Macrolipasemia
Macrolipasemia is the presence of serum lipase of a large molecular size, seen occasionally in otherwise healthy individuals, but more commonly in various diseases. Lipase is able to self-polymerize and/or form complexes with other blood proteins e.g. immunoglobulins.
Epidemiology
Epidemiologi...