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.
22 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
Thyroseq
Thyroseq® is an expanded gene classifier test designed for further evaluation of indeterminate thyroid nodules on fine needle aspiration (FNA). In particular, it is designed to further evaluate nodules that show atypia of undetermined significance/follicular lesion of undetermined significance (...
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
Lipoma
Lipomas are benign tumors composed of mature adipocytes. They are the most common soft tissue tumor, seen in ~2% of the population.
Epidemiology
Patients typically present in adulthood (5th-7th decades).
Associations
In some cases, multiple lipomas are associated with syndromes and other di...
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
Sinonasal polyposis
Sinonasal polyposis refers to the presence of multiple benign polyps in the nasal cavity and paranasal sinuses.
Epidemiology
Sinonasal polyposis is most commonly encountered in adults and rare in children. Polyps are the most common expansile lesions of the nasal cavity 8.
Associations
Condi...
Article
Non-pulsatile tinnitus
Non-pulsatile tinnitus is a form of tinnitus where there is a continuous ringing sensation of the ears. It is thought to have a considerable subjective component in many individuals.
Pathology
Many factors have been postulated, inclusive of 1-5:
cerumen impaction
middle ear infection
medica...
Article
WHO classification of eye tumors
The World Health Organizatiοn (WHO) classification of eye tumors is a widely used pathologic classification system of neoplasms of the orbit. The current revision, part of the 4th edition of the WHO series, was published in 2018 and is reflected in the article below 1.
Classification
Tumors of...
Article
Flail mandible
A flail mandible is an uncommon type of comminuted fracture through the mandibular symphysis and bilateral condyle and/or rami which can result in posterior displacement and internal rotation of the mandibular bodies, eversion of the angles of the mandible, and glossoptosis. Together with concom...
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
Parathyroid proliferative disease
Parathyroid proliferative disease is the collective term for a spectrum of parathyroid disorders 1:
parathyroid adenoma
parathyroid carcinoma
parathyroid atypical adenoma: controversial entity
parathyroid hyperplasia
primary chief cell hyperplasia
primary water-clear cell hyperplasia (rare...
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
Iodine
Iodine (chemical symbol I) is one of the trace elements. Its biological importance is its central place in the physiology of the thyroid gland and, in radiology, as the key chemical constituent of most of the radiographic, fluoroscopic, and CT contrast media.
Chemistry
Basic chemistry
Iodine ...
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
Charcot-Leyden crystals
Charcot-Leyden crystals consist of collections of bipyramidal crystalloid made up of eosinophilic membrane proteins, which occur in:
asthma
other eosinophilic lung disease 2
certain cases of sinusitis (e.g. allergic fungal sinusitis)
They may be detected in the sputum or sinus secretions wi...
Article
Cerumen
Cerumen, also known as earwax, is a natural secretion produced by and found within the external auditory canal (EAC). It has important roles as part of the first line of defense of the ear from micro-organisms and optimizing function of the tympanic membrane and EAC.
Secretion
Cerumen is secre...
Article
Hurthle cell
Hurthle cells are a type of oncocyte arising from thyroid follicular epithelial cells.
Terminology
The term Hurthle cell is now officially discouraged as the cells discovered by Hurthle were actually parafollicular C cells 5.
Pathology
Under microscopy, Hurthle cells are larger than typical ...
Article
Bethesda classification system for thyroid fine needle aspirates
Bethesda classification system for thyroid fine needle aspirates comprises six categories of pathological reporting of thyroid FNA, with each category linked to a malignancy risk.
Classification
category I: non-diagnostic
category II: benign
category III: atypia of undetermined sig...
Article
Pleomorphic adenoma of the salivary glands
Pleomorphic adenomas of the salivary glands, also known as benign mixed tumors (see below), are the most common salivary gland tumors. The salivary glands are the most common site of pleomorphic adenomas.
On imaging, they commonly present as well-circumscribed rounded masses, most commonly loca...
Article
Synechiae
Synechiae (singular: synechia, alternative plural: synechias) are another term for adhesions, which in radiological contexts usually relates to bands of scar tissue between structures, e.g. within the abdominal cavity or pleural cavity or within the uterus.
Pathology
Synechia can be found thro...
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