Lesion

: Pronounced "lee-sion" with the emphasis on the "lee," a lesion can be almost any abnormality involving any tissue or organ due to any disease or any injury. There are, not surprisingly, many types of lesions. There are also a number of different ways of classifying and naming lesions. Lesions can, for instance, be categorized according to whether or not they are caused by cancer. A benign lesion is non-cancerous whereas a malignant lesion is cancerous. For example, a biopsy of a skin lesion may prove it to be benign or malignant, or evolving into a malignant lesion (called a premalignant lesion). Lesions can be defined according to the patterns they form. For example, a bull's-eye or target lesion is one that looks like the bull's eye on a target. (In an X-ray of the duodenum, a bull's-eye lesion can represent a tumor with an ulcer (crater) in the center.) A coin lesion is a round shadow resembling a coin on a chest X-ray. It, too, is usually due to a tumor. Lesions can be named for persons who first described them. For instance, a Ghon lesion (or Ghon focus) is the scar-like "signature" in the lungs of adults left by tuberculosis in childhood. Lesions can also be categorized by their size. A gross lesion is one that can be seen with the naked eye. A microscopic or histologic lesion requires the magnification of a microscope to be seen. The basis of sickle cell disease is a molecular lesion, one that is not even visible with a microscope but is only detectable on the molecular (protein or DNA) level. Location is another basis for naming lesions. In neurology, a central lesion involves the brain or spinal cord, i.e., the central nervous system. A peripheral lesion involves the nerves away from the spinal cord and does not involve the central nervous system. There is a virtually endless assortment of lesions in medicine: primary lesions, secondary lesions, impaction lesions, indiscriminate lesions, irritative lesions, etc. Many are named for people including the Armanni-Ebstein lesion, a Bankart lesion, a Blumenthal lesion, and so on. The word "lesion" comes from the Latin noun "laesio" meaning "an attack or injury" which is related in Latin to the verb "laedere" = "to hurt, strike or wound."

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1. A wound or injury. 2. A pathologic change in the tissues. 3. One of the individual points or patches of a multifocal disease. [L. laedo, pp. laesus, to injure]

- Baehr-Lohlein l. SYN: Lohlein-Baehr l..

- Bankart l. a tear of the anterior glenoid labrum accompanying detachment of the inferior glenohumeral ligament.

- benign lymphoepithelial l. benign tumor-like masses of lymphoid tissue in the parotid gland, containing scattered small, mainly solid islands of epithelial cells. SYN: Godwin tumor.

- Bracht-Wächter l. a focal collection of lymphocytes and mononuclear cells within the myocardium in bacterial endocarditis.

- caviar l. a dilated vein or varicule existing in the venous collecting system under the tongue.

- coin l. of lungs SYN: nodular opacity.

- Dieulafoy l. an abnormally large submucosal artery located in the proximal stomach that may be the site of acute and recurrent episodes of massive hemorrhage.

- Duret l. small hemorrhage(s) in the floor of the fourth ventricle or beneath the aqueduct of Sylvius.

- Ghon primary l. SYN: Ghon tubercle.

- gross l. a l. plainly visible to the naked eye.

- high-grade squamous intraepithelial l. (HSIL, HGSIL) term used in the Bethesda system for reporting cervical/vaginal cytologic diagnosis to describe a spectrum of noninvasive cervical epithelial abnormalities, including moderate and severe dysplasia, carcinoma in situ, and cervical intraepithelial neoplasia grades 2 and 3. SEE ALSO: Bethesda system, ASCUS, atypical glandular cells of undetermined significance, under cell, low-grade squamous intraepithelial l..

- Hill-Sachs l. an irregularity seen in the head of the humerus following anterior dislocation of the shoulder; caused by impaction of posterolateral portion of the head of the humerus against the anterior edge of the glenoid.

- Janeway l. one of the stigmata of infectious endocarditis : irregular, erythematous, flat, painless macules on the palms, soles, thenar and hypothenar eminences of the hands, tips of the fingers, and plantar surfaces of the toes; rarely a diffuse rash. In acute endocarditis the lesions may be hemorrhagic or purple.

- Lohlein-Baehr l. focal embolic glomerulonephritis occurring in bacterial endocarditis. SYN: Baehr-Lohlein l..

- lower motor neuron l. injury to motor cells in the brainstem or spinal cord, or of the axons derived from them.

- low-grade squamous intraepithelial l. (LGSIL, LSIL) term used in the Bethesda system for reporting cervical/vaginal cytologic diagnosis to describe a spectrum of noninvasive cervical epithelial abnormalities; these lesions include the cellular changes associated with human papilloma virus cytopathologic effect and mild dysplasia (cervical intraepithelial neoplasia grade 1). SEE ALSO: Bethesda system, reactive changes, under change, ASCUS, atypical glandular cells of undetermined significance, under cell.

- Mallory-Weiss l. SYN: Mallory-Weiss syndrome.

- precancerous l. a noninvasive l. with a predictable likelihood of becoming malignant; e.g., actinic keratosis.

- radial sclerosing l. a variant of sclerosing adenosis of the breast with central scar formation and radiating hyperplastic ducts. SYN: radial scar.

- ring-wall l. a small ring hemorrhage in the brain that stimulates proliferation of a glial ring.

- supranuclear l. injury to cerebral descending (corticonuclear) fibers above the brainstem or spinal motor nerve nucleus. SYN: upper motor neuron l..

- upper motor neuron l. SYN: supranuclear l..

- wire-loop l. thickening of the basement membrane, with fibrinoid staining, of scattered peripheral capillaries in renal glomeruli; characteristic of renal involvement in systemic lupus erythematosus; the appearance of an affected capillary wall resembles a loop used in microbiology.

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le·sion 'lē-zhən n an abnormal change in structure of an organ or part due to injury or disease esp one that is circumscribed and well defined

le·sioned -zhənd adj

lesion vt to produce lesions in (as an animal's brain)

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n.

a zone of tissue with impaired function as a result of damage by disease or wounding. Apart from direct physical injury, examples of primary lesions include abscesses, ulcers, and tumours; secondary lesions (such as crusts and scars) are derived from primary ones.

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le·sion (leґzhən) [L. laesio; laedere to hurt] any pathological or traumatic discontinuity of tissue or loss of function of a part.