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.
40 results found
Article
Psammoma bodies
Psammoma bodies are round microscopic calcific collections. It is a form of dystrophic calcification. Necrotic cells form the focus for surrounding calcific deposition. They have a lamellated concentric calcified structure, sometimes large enough to be seen on CT.
Psammoma bodies are found in ...
Article
Human coronavirus
The human coronaviruses (hCoVs), members of the family Coronaviridae, are enveloped RNA viruses that affect humans, mammals and birds, causing both acute and chronic illnesses.
Four of the seven known human coronaviruses usually cause a mild coryzal illness only, these are HKU1, NL63, OC43, and...
Article
Tumor spread through air spaces
Tumor spread through air spaces (STAS) is a pattern of invasion in lung adenocarcinoma. According to the 2015 WHO classification, tumor spread through air spaces is defined as “micropapillary clusters, solid nests, or single cells spreading within air spaces beyond the edge of the main tumor” 2,...
Article
Metastatic axillary lymphadenopathy of unknown primary
Metastatic axillary lymphadenopathy of unknown primary can be a very challenging situation.
Pathology
Usual potential sites include:
occult breast cancer: the incidence of an axillary lymph node manifestation from an occult primary breast cancer is low, ranging from 0.3-0.8% of all patients ...
Article
ROS1 mutation
The ROS1 mutation is a mutation occurring in the ROS1 oncogene on chromosome 6 resulting in a defective receptor tyrosine kinase which has structural similarity to the anaplastic lymphoma kinase (ALK) protein.
It is thought to be present in several cancers of the subtype non-small cell lung can...
Article
Diverticulum
Diverticula are outpouchings of a hollow viscus and can be either true or false.
Occasionally a diverticulum is used in a more general sense to mean the outpouching of other anatomical structures, e.g. frontal intersinus septal cells are hypothesized to form as diverticula from the frontal sinu...
Article
Thyroid transcription factor 1
Thyroid transcription factor 1 (TTF1) refers to a homeodomain-containing nuclear transcription factor that belongs to the Nkx2 gene family encoded by a gene located on chromosome 14q13.
It is expressed in the forebrain, thyroid and lung tissues. The presence of TTF-1 protein on a tissue sample ...
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
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
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
Atypical pulmonary carcinoid tumor
An atypical pulmonary carcinoid tumor is a more aggressive variant of a pulmonary carcinoid tumor. They are less common and considered intermediate grade neoplasms and have the same “carcinoid morphology,” but with mitotic rates increased (at 2–10 mitoses per 2 mm2) where the tumor might also be...
Article
Peribronchiolar metaplasia
Peribronchiolar metaplasia is a partially recognized pathological entity characterized by fibrosis of the alveolar septa adjacent to terminal bronchioles and alveolar ducts, with bronchiolar-type epithelial metaplasia of the peribronchiolar alveolar walls. It is currently only accepted by some a...
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...
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
Oxygen
Oxygen (chemical symbol O) is one of the basic organic elements, and is a constituent of most of the known organic molecules - and therefore all lifeforms - on earth.
Chemistry
Basic chemistry
Oxygen is a colourless odorless diatomic gas with an atomic number 8 and atomic weight 15.999. It h...
Article
Aspergillus clavatus
Aspergillus clavatus is one of the species of Aspergillus that can cause pathology in humans. It is allergenic and causes a hypersensitivity pneumonitis called malt-workers lung.
See also
Aspergillus
Aspergillus fumigatus
Aspergillus flavus
Aspergillus clavatus
Article
Anaplastic lymphoma kinase (ALK) gene rearrangements
Anaplastic lymphoma kinase (ALK) gene rearrangements are known to occur in association with several tumors. The genes code for an enzyme called anaplastic lymphoma kinase (ALK) or ALK tyrosine kinase receptor (also known as CD246) which is thought to play a role in brain development and exerts i...
Article
Primary lung tumors in children
Pediatric primary lung tumors are rare in children however they must be distinguished from locally aggressive inflammatory conditions and benign disease. 1
Primary lung tumors in the neonates and infants include:
pleuropulmonary blastoma (PPB)
infantile fibrosarcoma of the lung
fetal lung in...
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