Articles
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More than 200 results
Article
Pathogen (epidemiology)
A pathogen is an agent that causes disease. Typically the term is used with infectious agents. An infected organism is termed the host. For humans most pathogens are prions, viruses, bacteria, fungi or parasites.
History and etymology
The prefix patho- is derived from the Ancient Greek pathos...
Article
Necrobiotic pulmonary nodules
Necrobiotic pulmonary nodules are sterile cavitating lung nodules associated with rheumatoid arthritis and inflammatory bowel disease (more often with ulcerative colitis than Crohn disease).
Epidemiology
They are more common in men 5.
Associations
Caplan syndrome
Clinical presentation
Us...
Article
Rubinstein-Taybi syndrome
Rubinstein-Taybi syndrome (RTS) is a very rare genetic multi-system disorder primarily characterized by intellectual disability, broad and often angulated thumbs and halluces, and distinctive facial features.
Epidemiology
The estimated incidence is 1 in 100,000-125,000 live births 5.
Clinical...
Article
Empty sella
An empty sella, also known as an empty pituitary fossa, refers to the appearance of the sella turcica when the pituitary gland appears shrunken or invisible and CSF fills the space instead. It is commonly an incidental finding of no clinical significance, but there exists a well-established asso...
Article
Temporal lobe epilepsy
Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy syndrome, with often characteristic imaging and clinical findings. It is divided into two broad groups:
medial epilepsy
most common
involves the mesial temporal lobe structures
most frequently due to mesial temporal scler...
Article
Congenital neuroblastoma
Congenital neuroblastoma is defined as neuroblastoma identified within a month of birth, and is divided into:
fetal neuroblastoma
neonatal neuroblastoma
In most cases they present as stage 1, 2 or 4S (see neuroblastoma staging).
Fetal neuroblastoma
In 90% of cases, fetal neuroblastomas aris...
Article
Childhood malignancies
Unfortunately the pediatric population is susceptible to malignancies. The most common entities, in overall order of frequency, are 1-4:
leukemia/lymphoma: ~35% *
acute lymphoblastic leukemia: 23%
Hodgkin disease: 5%
acute myelogenous leukemia: 4%
central nervous system malignancies: ~20%
...
Article
Target sign (pyloric stenosis)
The target sign of pyloric stenosis is a sign seen due to hypertrophied hypoechoic muscle surrounding echogenic mucosa, seen in pyloric stenosis. This is likened to a target.
See also
antral nipple sign (pyloric stenosis)
cervix sign (pyloric stenosis)
shoulder sign (pyloric stenosis)
Article
Cervix sign (pyloric stenosis)
The cervix sign of pyloric stenosis describes the indentation of the pylorus into the fluid-filled antrum, seen in pyloric stenosis on ultrasound examination.
See also
antral nipple sign (pyloric stenosis)
target sign (pyloric stenosis)
Article
Neuroblastoma (staging)
There are two methods of neuroblastoma staging; the International Neuroblastoma Risk Group Staging System (INRGSS, based on imaging of pre-treatment patients), and the International Neuroblastoma Staging System (INSS, based on the outcomes of surgery).
International Neuroblastoma Risk Group St...
Article
Double bubble sign (duodenum)
The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally 2.
Pathology
Causes include 1,2:
congenital obstruction
duodenal web
duodenal atresia
duodenal stenosis...
Article
Pulmonary infarction
Pulmonary infarction occurs secondary to vascular obstruction or occlusion 11. It is one of the key complications of pulmonary embolism (PE).
Epidemiology
Pulmonary infarction occurs in the minority (10-15%) of patients with PE 1. However, in a necropsy study of those with lethal PE, 60% of c...
Article
Honeycombing (lungs)
Honeycombing describes small adjacent subpleural cystic structures in the context of established pulmonary fibrosis with destruction of lung parenchyma and loss of architecture 11. A single layer of cysts is now considered sufficient to apply this descriptor if other signs of pulmonary fibrosis ...
Article
Facial nerve
The facial nerve is the seventh (CN VII) cranial nerve and comprises two roots, a motor root and a smaller mixed sensory, taste and parasympathetic root, known as nervus intermedius, which join together within the temporal bone (TA: nervus facialis or nervus cranialis VII).
The facial nerve has...
Article
Upper lobe pulmonary venous diversion
Upper lobe pulmonary venous diversion, also described as cephalisation of the pulmonary veins, reflects blood flow redistribution to the apices in chronic heart failure 5,6.
Clinical presentation
The normal left atrial pressure is 5-10 mmHg; elevation of left atrial pressures to 10-15 mmHg wil...
Article
WHO classification of anal margin tumors (historical)
The WHO classification of anal margin tumors or perianal skin tumors was included in the Pathology and Genetics of Tumors of the Digestive System published in 2000, and these tumors were classified as skin tumors 1,2.
In the latest WHO Classification of Tumors edition (Digestive System Tumors ...
Article
WHO classification of tumors of the anal canal
The 2019 WHO Classification of Digestive System Tumors (5th ed.) lists the following tumors of the anal canal 1,2. Anal margin tumors are now considered in the anal canal classification 3.
Classification
Epithelial tumors
benign epithelial tumors and precursors
inflammatory cloacogenic polyp...
Article
Primary uveal malignant melanoma
Malignant uveal melanomas, also referred to as choroidal melanomas, are the most common primary tumor of the adult eye 3.
Epidemiology
Malignant melanoma of the uvea is the most common primary intraocular malignancy and is predominantly seen in the White population 5. The incidence of these t...
Article
Arrhythmogenic right ventricular cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy (ARVC), also referred to as arrhythmogenic right ventricular dysplasia (ARVD) or simply arrhythmogenic cardiomyopathy, is a cardiomyopathy that is one of the more common causes of sudden cardiac death in young patients.
Epidemiology
The estimate...
Article
Lipiodol
Lipiodol (also known as ethiodized oil) is an oil-based iodinated contrast medium that was historically used for myelography and hysterosalpingography 1. Newer, less hazardous agents later superseded it and are now used primarily as therapeutic agents. Guerbet was previously the sole manufacture...
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