Skeletal Muscle - Inflammation








comment:
Inflammation of skeletal muscle can occur as a result of numerous types of injury, including physical trauma (e.g., injection sites, bite wounds, and blunt trauma), exposure to myotoxins or infectious agents, and ischemia, thrombosis, or myofiber necrosis. Inflammation can exhibit various morphologic patterns. It can be primarily interstitial, with little or no myofiber necrosis, or can be the predominant feature, with little inflammation.In NTP studies, there are five standard categories of inflammation: acute, suppurative, chronic, chronic-active, and granulomatous; abscesses are diagnosed as suppurative inflammation. In acute inflammation ( Figure 1








Since inflammation can occur in response to, or result in, myofiber necrosis, myopathic changes in addition to edema and/or hemorrhage often occur concurrently. An inflammatory response is necessary to effectively repair damaged tissues; however, the nature, duration, and intensity of this response will crucially influence the overall outcome of repair.
recommendation:
Inflammation should be diagnosed and graded whenever it is considered a primary lesion. It may be diagnosed as a secondary lesion (e.g., secondary to necrosis) if it is particularly severe or more severe than expected relative to the severity of the primary lesion. The diagnosis should include the type of inflammation (e.g., acute, chronic, chronic-active) as a modifier. Generally it is not necessary to include a site modifier unless it is needed to separate two distinct lesions. Associated lesions, such as vascular lesions, foreign bodies, or infectious agents, should be diagnosed separately. Lesions secondary to the inflammation (e.g., necrosis) and lesions that are part of the inflammatory process (e.g., edema or hemorrhage) should not be diagnosed separately unless warranted by severity but should be described in the pathology narrative.references:
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Web page last updated on: March 13, 2015