A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. Lesion is derived from the Latin laesio meaning "injury". Lesions may occur in plants as well as animals.
| Lesion | |
|---|---|
| Specialty | Pathology |
Types
There is no designated classification or naming convention for lesions. Since lesions can occur anywhere in the body and the definition of a lesion is so broad, the varieties of lesions are virtually endless. Generally, lesions may be classified by their patterns, their sizes, their locations, or their causes. They can also be named after the person who discovered them. For example, Ghon lesions, which are found in the lungs of those with tuberculosis, are named after the lesion's discoverer, Anton Ghon. The characteristic skin lesions of a varicella zoster virus infection are called chickenpox. Lesions of the teeth are usually called dental caries, or "cavities".
Location
Lesions are often classified by their tissue types or locations. For example, a "skin lesion" or a "brain lesion" are named for the tissue where they are found. If there is an added significance to regions within the tissue—such as in neural injuries where different locations correspond to different neurological deficits—they are further classified by location. For example, a lesion in the central nervous system is called a central lesion, and a lesion in the peripheral nervous system is called a peripheral lesion. A myocardial lesion results from damage to the heart muscle, and a coronary lesion is a subtype that describes a lesion in the coronary arteries. Coronary lesions are then further classified according to the side of the heart that is affected and the diameter of the artery in which they form.
Cause and behavior
If a lesion is caused by a tumor, it can be classified as malignant or benign after analysis of a biopsy. A benign lesion that is evolving into a malignant lesion is called "premalignant". Cancerous lesions are sometimes classified by their growth kinetics, such as the Lodwick classification, which characterizes classes of bone lesions. Another type is an excitotoxic lesion, which can be caused by excitatory amino acids like kainic acid that kill neurons through overstimulation.
Size and shape
Lesion size may be specified as gross, meaning it is visible to the unaided eye, or histologic, meaning a microscope is needed to see it. A space-occupying lesion, as the name suggests, has a recognizable volume and may impinge on nearby structures, whereas a non space-occupying lesion is simply a hole in the tissue, e.g. a small area of the brain that has turned to fluid following a stroke.
Lesions may also be classified by the shape they form. This is the case with many ulcers, which can have a bullseye or 'target' appearance. A coin lesion as seen in an X-ray has the appearance of a coin sitting on the patient's chest.
Research using lesions
Brain lesions may help researchers understand brain function. Research involving lesions relies on two assumptions: that brain damage can affect different aspects of cognition independently, and that a locally damaged brain functions identically to a normal brain in its "undamaged" parts.
Sham lesion is the name given to a control procedure during a lesion experiment. In a sham lesion, an animal may be placed in a stereotaxic apparatus and electrodes inserted as in the experimental condition, but no current is passed, and therefore damage to the tissue should be minimal.
Research with humans
Humans with brain lesions are often the subjects of research with the goal of establishing the function of the area where their lesion occurred.
A drawback to the use of human subjects is the difficulty in finding subjects who have a lesion to the area the researcher wishes to study. As such, transcranial magnetic stimulation is often used in cognition and neuroscience-related tests to imitate the effect.
Research with animals
Using animal subjects gives researchers the ability to study lesions in specific body parts of the subjects, allowing them to quickly acquire a large group of subjects. An example of such a study is the lesioning of rat hippocampi to establish the role of the hippocampus in object recognition and object recency.
Notable lesions
- Morel-Lavallee lesion
- Bankart lesion
- Perthes Lesion
- Stener lesion
- SLAP lesion
Diabetes-associated lesions
Bone lesions
- Non-ossifying fibroma
- ALPSA lesion
- Hill–Sachs lesion
- Osteoporosis circumscripta
- Osteolytic lesion
Brain lesions
- Olney's lesions
Skin lesions
- Melanocytic nevus
- Skip lesion
- Osler's node
- Keratoderma blennorrhagicum
- Dermatosis papulosa nigra
- Leukemid
- Janeway lesion
- Kaposi's sarcoma
- Nevus spilus
- Chronic scar keratosis
Gastrointestinal lesions
- Dieulafoy's lesion
- Cameron lesions
Endodermal lesions
- Melanocytic oral lesion
- Endometrial intraepithelial neoplasia
Misc. disease-associated lesions
- Ghon focus
- Benign lymphoepithelial lesion
- Multiple sclerosis lesions
- Herpes labialis
- Tropical ulcer
- Herpetic whitlow
See also
- Ablation
References
- "Lesion...What Does The Doctor Mean?". MedicineNet. Archived from the original on March 27, 2003. Retrieved 2016-03-03.
- Farooq, Vasim; Brugaletta, Salvatore; Serruys, Patrick W. (2011-12-01). "Contemporary and evolving risk scoring algorithms for percutaneous coronary intervention". Heart. 97 (23): 1902–1913. doi:10.1136/heartjnl-2011-300718. ISSN 1468-201X. PMID 22058284. S2CID 23254704.
- Bennett, D. Lee; El-Khoury, Georges H. (6 May 2004). "General approach to lytic bone lesions". Appliedradiology.com. Retrieved 2016-03-03.
- Leeson, Thomas S.; Leeson, C. Roland (1981). Histology (Fourth ed.). W. B. Saunders Company. p. 600. ISBN 978-0-7216-5704-2.
- Stedman's medical dictionary (27th ed.). Lippincott Williams & Wilkins. 2006. ISBN 068340007X.
- Kosslyn, Stephen M.; Intriligator, James M. (1992). "Is Cognitive Neuropsychology Plausible? The Perils of Sitting on a Juan-Legged Stool". Journal of Cognitive Neuroscience. 4 (1): 96–105. doi:10.1162/jocn.1992.4.1.96. PMID 23967860. S2CID 15557071.
- Adolphs, Ralph (2016-06-15). "Human Lesion Studies in the 21st Century". Neuron. 90 (6). Pubmed Central: 1151–1153. doi:10.1016/j.neuron.2016.05.014. PMC 5656290. PMID 27311080.
- Sliwinska, M. W., Vitello, S., & Devlin, J. T. (2014). Transcranial magnetic stimulation for investigating causal brain-behavioral relationships and their time course. Journal of visualized experiments : JoVE, (89), 51735. doi:10.3791/51735
- Albasser, Amin, Lin, Iordanova, Aggelton. Evidence That the Rat Hippocampus Has Contrasting Roles in Object Recognition Memory and Object Recency Memory
External links
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Definitions from Wiktionary![image]()
Media from Commons
A lesion is any damage or abnormal change in the tissue of an organism usually caused by injury or diseases Lesion is derived from the Latin laesio meaning injury Lesions may occur in plants as well as animals LesionSpecialtyPathologyTypesThere is no designated classification or naming convention for lesions Since lesions can occur anywhere in the body and the definition of a lesion is so broad the varieties of lesions are virtually endless Generally lesions may be classified by their patterns their sizes their locations or their causes They can also be named after the person who discovered them For example Ghon lesions which are found in the lungs of those with tuberculosis are named after the lesion s discoverer Anton Ghon The characteristic skin lesions of a varicella zoster virus infection are called chickenpox Lesions of the teeth are usually called dental caries or cavities Location Lesions are often classified by their tissue types or locations For example a skin lesion or a brain lesion are named for the tissue where they are found If there is an added significance to regions within the tissue such as in neural injuries where different locations correspond to different neurological deficits they are further classified by location For example a lesion in the central nervous system is called a central lesion and a lesion in the peripheral nervous system is called a peripheral lesion A myocardial lesion results from damage to the heart muscle and a coronary lesion is a subtype that describes a lesion in the coronary arteries Coronary lesions are then further classified according to the side of the heart that is affected and the diameter of the artery in which they form Cause and behavior If a lesion is caused by a tumor it can be classified as malignant or benign after analysis of a biopsy A benign lesion that is evolving into a malignant lesion is called premalignant Cancerous lesions are sometimes classified by their growth kinetics such as the Lodwick classification which characterizes classes of bone lesions Another type is an excitotoxic lesion which can be caused by excitatory amino acids like kainic acid that kill neurons through overstimulation Size and shape Lesion size may be specified as gross meaning it is visible to the unaided eye or histologic meaning a microscope is needed to see it A space occupying lesion as the name suggests has a recognizable volume and may impinge on nearby structures whereas a non space occupying lesion is simply a hole in the tissue e g a small area of the brain that has turned to fluid following a stroke Lesions may also be classified by the shape they form This is the case with many ulcers which can have a bullseye or target appearance A coin lesion as seen in an X ray has the appearance of a coin sitting on the patient s chest Research using lesionsBrain lesions may help researchers understand brain function Research involving lesions relies on two assumptions that brain damage can affect different aspects of cognition independently and that a locally damaged brain functions identically to a normal brain in its undamaged parts Sham lesion is the name given to a control procedure during a lesion experiment In a sham lesion an animal may be placed in a stereotaxic apparatus and electrodes inserted as in the experimental condition but no current is passed and therefore damage to the tissue should be minimal Research with humans Humans with brain lesions are often the subjects of research with the goal of establishing the function of the area where their lesion occurred A drawback to the use of human subjects is the difficulty in finding subjects who have a lesion to the area the researcher wishes to study As such transcranial magnetic stimulation is often used in cognition and neuroscience related tests to imitate the effect Research with animals Using animal subjects gives researchers the ability to study lesions in specific body parts of the subjects allowing them to quickly acquire a large group of subjects An example of such a study is the lesioning of rat hippocampi to establish the role of the hippocampus in object recognition and object recency Notable lesionsSoft tissue lesions Morel Lavallee lesion Bankart lesion Perthes Lesion Stener lesion SLAP lesion Diabetes associated lesions Bone lesions Non ossifying fibroma ALPSA lesion Hill Sachs lesion Osteoporosis circumscripta Osteolytic lesion Brain lesions Olney s lesions Skin lesions Melanocytic nevus Skip lesion Osler s node Keratoderma blennorrhagicum Dermatosis papulosa nigra Leukemid Janeway lesion Kaposi s sarcoma Nevus spilus Chronic scar keratosis Gastrointestinal lesions Dieulafoy s lesion Cameron lesions Endodermal lesions Melanocytic oral lesion Endometrial intraepithelial neoplasia Misc disease associated lesions Ghon focus Benign lymphoepithelial lesion Multiple sclerosis lesions Herpes labialis Tropical ulcer Herpetic whitlowSee alsoAblationReferences Lesion What Does The Doctor Mean MedicineNet Archived from the original on March 27 2003 Retrieved 2016 03 03 Farooq Vasim Brugaletta Salvatore Serruys Patrick W 2011 12 01 Contemporary and evolving risk scoring algorithms for percutaneous coronary intervention Heart 97 23 1902 1913 doi 10 1136 heartjnl 2011 300718 ISSN 1468 201X PMID 22058284 S2CID 23254704 Bennett D Lee El Khoury Georges H 6 May 2004 General approach to lytic bone lesions Appliedradiology com Retrieved 2016 03 03 Leeson Thomas S Leeson C Roland 1981 Histology Fourth ed W B Saunders Company p 600 ISBN 978 0 7216 5704 2 Stedman s medical dictionary 27th ed Lippincott Williams amp Wilkins 2006 ISBN 068340007X Kosslyn Stephen M Intriligator James M 1992 Is Cognitive Neuropsychology Plausible The Perils of Sitting on a Juan Legged Stool Journal of Cognitive Neuroscience 4 1 96 105 doi 10 1162 jocn 1992 4 1 96 PMID 23967860 S2CID 15557071 Adolphs Ralph 2016 06 15 Human Lesion Studies in the 21st Century Neuron 90 6 Pubmed Central 1151 1153 doi 10 1016 j neuron 2016 05 014 PMC 5656290 PMID 27311080 Sliwinska M W Vitello S amp Devlin J T 2014 Transcranial magnetic stimulation for investigating causal brain behavioral relationships and their time course Journal of visualized experiments JoVE 89 51735 doi 10 3791 51735 Albasser Amin Lin Iordanova Aggelton Evidence That the Rat Hippocampus Has Contrasting Roles in Object Recognition Memory and Object Recency MemoryExternal linksLesion at Wikipedia s sister projects Definitions from WiktionaryMedia from Commons
