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.
53 results found
Article
Malignant transformation
Malignant transformation is the term given to the process whereby either normal, metaplastic, or benign neoplastic tissue, becomes a cancer. The process usually occurs in a series of steps and the affected tissue gradually accumulates the genetic mutations that express a malignant phenotype. The...
Article
Neoplasm
Neoplasms, also known as tumors, are pathological masses, caused by cells abnormally proliferating and/or not appropriately dying. Neoplasms may be either benign or malignant. Malignant neoplasms are synonymous with cancers.
Benign neoplasms
clear origin (unless very large)
slow growth
usua...
Article
Prostatic acid phosphatase
Prostatic acid phosphatase (PAP) also known as prostatic specific acid phosphatase (PSAP) is an enzyme generated by prostatic glandular tissue.
Usage
It can be used in immunohistochemistry to identify prostatic tissue including prostatic epithelium and prostatic ducts and is usually expressed ...
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
CSF alpha-fetoprotein
Alpha-fetoprotein (AFP) in the cerebrospinal spinal fluid (CSF) has been reported as a tumor marker for some intracranial tumors with yolk sac elements, and teratoma 1.
Interpretation
Elevation
intracranial yolk sac tumor
intracranial embryonal carcinoma
congenital CNS tumors with yolk sac ...
Article
CDKN2A/p16
CDKN2A (cyclin-dependent kinase inhibitor 2A) is a tumor suppressor gene that encodes for the p16 protein, involved in the CDK4/6–RB1 cell-cycle pathway 5.
p16 is a widely used immunohistochemical marker indicating expression of the cell cycle protein, which is upregulated by human papillomavi...
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
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
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
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
Tumor markers
Tumor markers are a group of molecules in serum that are elevated in various malignancies and are often used to monitor treatment response as well as alert for potential progressive disease when in remission.
Commonly used markers include:
AFP (alpha fetoprotein)
beta-hCG
CA 15-3
CA 19-9
C...
Article
BRAF
BRAF (B-Raf proto-oncogene serine/threonine-protein kinase) is a proto-oncogene, encoding for a serine/threonine protein kinase. Mutations of BRAF are the most common alteration of the RAS/MAPK pathway and these have been identified in a variety of tumors and congenital syndromes including 1-5: ...
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
Lepidic growth
Lepidic growth is a pathological term referring to a pattern of cell proliferation along the lining of the alveolar structures of the lung as is seen in a subset of lung tumors 1.
History and etymology
‘lepidic’ was coined by the English pathologist John George Adam (1862-1926) whilst at McGil...
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
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
CA 27-29
CA 27-29 is a tumor marker and is a soluble form of glycoprotein MUC1. It may be elevated in patients with breast cancer. Tumors of the colon, stomach, kidney, lung, ovary, pancreas, uterus, and liver may also raise CA 27-29 levels.
Certain non-malignant conditions are also associated with its ...
Article
Extranodal extension
Extranodal extension refers to the growth of a nodal cancer metastasis beyond the confines of the capsule of a lymph node into adjacent tissues. Less preferred synonyms include extranodal spread, extracapsular extension, or extracapsular spread.
This finding holds prognostic implications. For e...
Article
Circumferential resection margin
Circumferential resection margin (CRM) is a term used to denote the standard plane of excision of total mesorectal excision, used for resection of rectal cancers. The anatomic correlate is the mesorectal fascia. The distance between tumor tissue or satellite tumor deposits and the mesorectal fas...
Article
Exophytic
Exophytic is a descriptive term used by radiologists/pathologists to describe solid organ lesions arising from the outer surface of the organ of origin.
Literally exophytic only refers to those lesions arising from the outer surface, however radiologists and pathologists use the term to include...
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