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Hyperplasia

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Hyperplasia
Whereashypertrophystems from an increase incell size,hyperplasia results from an increase in cell number.
SpecialtyPathology
TypesBenign prostatic hyperplasia, Hyperplasia of the breast(many more)[1][2]
Diagnostic methodBiopsy[3]
TreatmentDepends which type (see types)

Hyperplasia(fromancient Greekὑπέρhuper'over' + πλάσιςplasis'formation'), orhypergenesis,is an enlargement of an organ or tissue caused by an increase in the amount oforganic tissuethat results fromcell proliferation.[4]It may lead to thegross enlargementof an organ, and the term is sometimes confused with benignneoplasiaorbenign tumor.[5]

Hyperplasia is a common preneoplastic response to stimulus.[6]Microscopically, cells resemble normal cells but are increased in numbers. Sometimes cells may also be increased in size (hypertrophy).[7]Hyperplasia is different from hypertrophy in that theadaptive cell changein hypertrophy is an increase in thesizeof cells,whereas hyperplasia involves an increase in thenumberof cells.[8]

Causes

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Hyperplasia may be due to any number of causes, including proliferation of basal layer of epidermis to compensate skin loss,chronic inflammatory response,hormonal dysfunctions,orcompensationfordamageordiseaseelsewhere.[9]Hyperplasia may be harmless and occur on a particular tissue. An example of a normal hyperplastic response would be the growth and multiplication of milk-secretingglandularcells in thebreastas a response topregnancy,thus preparing for futurebreast feeding.[10]

Perhaps the most interesting and potent[editorializing]effectinsulin-like growth factor 1(IGF) has on the human body is its ability to cause hyperplasia, which is an actual splitting of cells.[11]By contrast,hypertrophyis what occurs, for example, to skeletal muscle cells duringweight trainingand is simply an increase in the size of the cells.[12]With IGF use, one is able to cause hyperplasia which actually increases the number of muscle cells present in the tissue.[13]Weight training enables these new cells to mature in size and strength. It is theorized that hyperplasia may also be induced through specific power output training for athletic performance, thus increasing the number of muscle fibers instead of increasing the size of a single fiber.[14]

Mechanism

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Hyperplasia is considered to be aphysiological(normal) response to a specific stimulus, and the cells of a hyperplastic growth remain subject to normalregulatory controlmechanisms.[5]However, hyperplasia can also occur as apathologicalresponse, if an excess of hormone or growth factor is responsible for the stimuli. Similarly to physiological hyperplasia, cells that undergo pathologic hyperplasia are controlled bygrowth hormones,and cease to proliferate if such stimuli are removed.[15]This differs fromneoplasia(the process underlyingcancerand benign tumors), in whichgenetically abnormal cellsmanage toproliferatein a non-physiological manner which is unresponsive to normal stimuli.[16]That being said, the effects caused by pathologic hyperplasia can provide a suitable foundation from which neoplastic cells may develop.[15]

Role in disease

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Hyperplasia of certain tissues may cause disease. Pathologic hyperplasia in these tissues may occur due to infection, physiological stress or trauma, or abnormal levels of particular hormones, such as estrogen, ACTH, or cortisol.[17]

Types

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Some of the more commonly known clinical forms of hyperplasia, or conditions leading to hyperplasia, include:

Patient with hemihyperplasia involving the upper and lower left extremities. Theleg length discrepancycan be noted by the pelvic tilt.
  • Hemihyperplasia– When only half (or one side) of the body is affected, sometimes generating limbs of different lengths.[21]
  • Hyperplasia of the breast– "Hyperplastic" lesions of thebreastincludeusual ductal hyperplasia,a focal expansion of the number of cells in a terminal breast duct, andatypical ductal hyperplasia,in which a more abnormal pattern of growth is seen, and which is associated with an increased risk of developing breast cancer.[2]
  • Intimal hyperplasia– The thickening of thetunica intimaof a blood vessel as a complication of a reconstruction procedure orendarterectomy.Intimal hyperplasia is the universal response of a vessel to injury and is an important reason of late bypass graft failure, particularly in vein and synthetic vascular grafts.[22]
  • Focal epithelial hyperplasia(also known as Heck's disease) – This is a wart-like growth in the mucous tissues of the mouth or, rarely, throat that is caused by certain sub-types of thehuman papillomavirus(HPV). Heck's disease has not been known to cause cancer.[23]
  • Myofibre hyperplasia (also known asdouble-muscling) – seen in cattle, genetic mutations cause large muscles due to increased proliferation of myofibres and decreased adipose tissue.[24]
  • Sebaceous hyperplasia– In this condition, small yellowish growths develop on the skin, usually on the face. This condition is neither contagious nor dangerous.[25]
  • Compensatoryliverhyperplasia– The liver undergoes cellular division after acute injury, resulting in new cells that restore liver function back to baseline. Approximately 75% of the liver can be acutely damaged or resected with seemingly full regeneration throughhepatocytedivision, i.e., hyperplasia. This is what makes living-donor liver transplants possible.[26]
  • Epidermal hyperplasiaof the skin[citation needed]

See also

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References

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  1. ^ab"Prostate Enlargement (Benign Prostatic Hyperplasia)".National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).U.S. Department of Health and Human Services National Institutes of Health.Retrieved2015-05-30.
  2. ^abKoerner FC (2009).Diagnostic Problems in Breast Pathology.Elsevier Health Sciences.ISBN978-1-4160-2612-9.
  3. ^Dunphy LM, Winland-Brown JE (April 2011).Primary Care: The Art and Science of Advanced Practice Nursing.F.A. Davis.ISBN978-0-8036-2647-8.
  4. ^"Hyperplasia".MedlinePlus Medical Encyclopedia.National Library of Medicine, U.S. Department of Health and Human Services National Institutes of Health.Retrieved2015-05-30.
  5. ^abSembulingam K, Sembulingam P (September 2012).Essentials of Medical Physiology.JP Medical Ltd.ISBN9789350259368.
  6. ^Zachary JF, McGavin MD (December 2013).Pathologic Basis of Veterinary Disease.Elsevier Health Sciences.ISBN978-0-323-29172-9.
  7. ^Braun CA, Anderson CM (2007).Pathophysiology: Functional Alterations in Human Health.Lippincott Williams & Wilkins. p.17.ISBN978-0-7817-6250-2.
  8. ^Rubin E, Reisner HM (2009).Essentials of Rubin's Pathology.Lippincott Williams & Wilkins.ISBN978-0-7817-7324-9.
  9. ^Porth C (2011).Essentials of Pathophysiology: Concepts of Altered Health States.Lippincott Williams & Wilkins.ISBN978-1-58255-724-3.
  10. ^Dirbas F, Scott-Conner C (January 2011).Breast Surgical Techniques and Interdisciplinary Management.Springer Science & Business Media.ISBN978-1-4419-6076-4.
  11. ^Gardiner P.Advanced Neuromuscular Exercise Physiology.Human Kinetics.ISBN978-1-4504-1227-8.
  12. ^Metzl JD, Shookhoff C (October 2009).The Young Athlete: A Sports Doctor's Complete Guide for Parents.Little, Brown.ISBN978-0-316-08673-8.
  13. ^Rodgers K, ed. (November 2011).The Endocrine System.Britannica Educational Publishing.ISBN978-1-61530-731-9.
  14. ^Kisner C, Colby LA (December 2012).Therapeutic Exercise: Foundations and Techniques.F.A. Davis.ISBN978-0-8036-3897-6.
  15. ^abcKumar V, Abbas A, Aster J (2013).Robbins Basic Pathology.Philadelphia, US: Elsevier. p. 4.ISBN978-0-8089-2432-6.
  16. ^Hong WK, Hait WN (2010).Holland Frei Cancer Medicine Eight.PMPH-USA.ISBN978-1-60795-014-1.
  17. ^Kemp WL, Burns DK, Brown TG."Pathology: The Big Picture".AccessMedicine.McGraw Hill Medical.Retrieved2021-12-06.
  18. ^"Cushing disease".MedlinePlus Medical Encyclopedia.National Library of Medicine, U.S. Department of Health and Human Services National Institutes of Health.Retrieved2015-05-30.
  19. ^"Congenital adrenal hyperplasia".MedlinePlus Medical Encyclopedia.National Library of Medicine, U.S. Department of Health and Human Services National Institutes of Health.Retrieved2015-05-30.
  20. ^"Endometrial Hyperplasia".American College of Obstetricians and Gynecologists (ACOG).Retrieved2015-05-30.
  21. ^"Hemihyperplasia - Glossary Entry".Genetics Home Reference.National Library of Medicine, U.S. Department of Health and Human Services.Retrieved2015-05-30.
  22. ^Subbotin VM (October 2007)."Analysis of arterial intimal hyperplasia: review and hypothesis".Theoretical Biology & Medical Modelling.4:41.doi:10.1186/1742-4682-4-41.PMC2169223.PMID17974015.
  23. ^Purkait SK (2011).Essentials of Oral Pathology.JP Medical Ltd.ISBN9789350252147.
  24. ^Swatland, Howard (January 1974)."Developmental disorders of skeletal muscle in cattle, pigs and sheep".The Veterinary Bulletin.44(4): 187–189 – via ResearchGate.
  25. ^Evans CC, High WA (October 2011).Skin Diseases in the Elderly: A Color Handbook.CRC Press.ISBN978-1-84076-615-8.
  26. ^Kumar V, Abbas AK, Aster JC (September 2014).Robbins & Cotran Pathologic Basis of Disease.Elsevier Health Sciences.ISBN978-0-323-29635-9.

Further reading

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