Liver Necrosis - Revision history

Fiorecastro at 17:06, 5 January 2023

2023-01-05T17:06:37Z

Bara at 14:31, 16 September 2011

2011-09-16T14:31:50Z

Bara at 13:48, 16 September 2011

2011-09-16T13:48:29Z

Bara at 13:43, 16 September 2011

2011-09-16T13:43:14Z

Bara at 13:32, 16 September 2011

2011-09-16T13:32:02Z

Bara at 23:06, 25 July 2011

2011-07-25T23:06:13Z

Bara at 22:33, 25 July 2011

2011-07-25T22:33:10Z

Bara at 13:10, 20 April 2011

2011-04-20T13:10:14Z

Kthompson: /* Random foci (focal) */

2011-03-30T16:06:40Z

Random foci (focal)

Kthompson at 16:06, 30 March 2011

2011-03-30T16:06:03Z

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 |date = September 09, 2011
 }}
 [[Category:Liver_-_General_Pathology]]
 [[Category:Nicola Parry reviewed]]

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 This is another uncommon pattern of necrosis that only involves a region around the central vein. It is caused by direct-acting hepatotoxins, and is seen in cases of phosphorus poisoning.
-Regardless of the zone affected, grossly the liver is pale, friable, slightly enlargedwith rounded edges, and has an enhanced lobular pattern.
+Regardless of the zone affected, grossly the liver is pale, friable, slightly enlarged with rounded edges, and has an enhanced lobular pattern.
 === Massive Necrosis ===
-This occurs when there is necrosis of a complete acinus or an even larger area of tissue. It encompasses large areas of liver cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ.
+This pattern does not imply necrosis of the whole liver, but rather describes necrosis that spans an entire lobule or adjacent lobules. All hepatocytes within the affected lobule(s) are necrotic.
-==Subacute Cytolytic Necrosis==
+Since all hepatocytesin the lobule are affected, regeneration of these regions is not possible, and affected lobules collapse. In acute stages, the liver may be enlarged or swollen due to congestion. Later, it may reduce in size as a result of scarring that occurs subsequent to lobular collapse (post-necrotic scarring).
-==''Hepatosis dietica''==
+'''''Hepatosis dietica''''' is one condition that results in massive necrosis due to vitamin E and selenium deficiency. This occurs in rapidly growing pigs that are fed on large quantities of grain concentrates, or poor quality or low quantity protein supplements. The exact pathogenesis is still poorly understood, but the resultant nutritional deficiencies of selenium and Vitamin E are considered to generate free radicals that result in liver necrosis.
 {{Learning
@@ Line 44: / Line 40: @@
 == References ==
-Blood, D.C. and Studdert, V. P. (1999) '''Saunders Comprehensive Veterinary Dictionary '''(2nd Edition),'' Elsevier Science.''
+Blood, D.C. and Studdert, V. P. (1999) '''Saunders Comprehensive Veterinary Dictionary '''(2nd Edition), '' Elsevier Science.''
 <br>
 Ettinger, S.J, Feldman, E.C. (2005) '''Textbook of Veterinary Internal Medicine '''(6th edition, volume 2),'' W.B. Saunders Company.''
 <br>
-Fossum, T. W. et. al. (2007) '''Small Animal Surgery''' (Third Edition),'' Mosby Elsevier.''
+Fossum, T. W. et. al. (2007) '''Small Animal Surgery''' (Third Edition), '' Mosby Elsevier.''
 <br>
-Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine '''(Fourth Edition)'', Mosby Elsevier. ''
+Smyth, B (2008) '''Alimentary System Study Guide''''', Royal Veterinary College''.
 [[Category:Liver_-_General_Pathology]]
-[[Category:Nicola Parry reviewing]]
+[[Category:Nicola Parry reviewed]]

@@ Line 20: / Line 20: @@
 This is the most common type of zonal necrosis and occurs mainly due to the fact that hepatocytes in this central zone are furthest away from the incoming blood supply. They are therefore more susceptible to hypoxia. Additionally, they contain the greatest concentration of cytochrome p450 enzymes that metabolise substances into more reactive metabolites capable of killing the hepatocytes. Therefore toxic insults and conditions leasing to hypoxia commonly produce this pattern of necrosis. Some viral conditions, however, also result in centrilobular necrosis, such as '''[[Infectious Canine Hepatitis]] (ICH)'''. This is a highly infectious disease of young dogs caused by canine adenovirus-1. It is now rare in the UK and US due to effective vaccination protocols.
-===Midzonal===
+'''Midzonal'''<br>
-Midzonal necrosis is rare and is mainly seen in pigs with aflatoxicosis. It is also seen in humans suffering from 'Yellow Fever'.
+This pattern of necrosis is rare in animals although is mainly seen in horses and pigs with aflatoxicosis. It is also seen in people suffering from 'Yellow Fever'.
-======Periportal (Centroacinar)======
+'''Periportal (Centroacinar)'''<br>
-Centroacinar necrosis is also rare. This has been seen in cases of phosphorous poisoning.
+This is another uncommon pattern of necrosis that only involves a region around the central vein. It is caused by direct-acting hepatotoxins, and is seen in cases of phosphorus poisoning.
 === Massive Necrosis ===

@@ Line 12: / Line 12: @@
 *[[Toxoplasmosis - Cat and Dog|Toxoplasmosis]] in dogs and cats
+If grossly visible, necrotic foci appear as discrete white or red foci that range from one to many millimetres in diameter.
 == Zonal Necrosis ==
-Zonal necrosis is necrosis occurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule:
+This type of change affects hepatocytes in defined anatomic regions of the liver lobule:
-===Periacinar (Centrilobular)===
+'''Periacinar (Centrilobular)'''<br>
-This is the most common type of zonal necrosis and occurs mainly due to the fact that the hepatocytes in this zone are furthest away from the incoming blood supply and are therefore less oxygenated and relatively anoxic. They are reported to contain the greatest number of enzymes responsible for metabolising substances to more toxic metabolites capable of killing the hepatocytes. Therefore hypoxic states and toxic substances predominate in this type of necrosis, although some viral conditions also are the cause, such as '''[[Infectious Canine Hepatitis]] (ICH)'''. This is a highly infectious disease of young dogs which is spread by urine. It is now rare due to vaccination in the UK.
+This is the most common type of zonal necrosis and occurs mainly due to the fact that hepatocytes in this central zone are furthest away from the incoming blood supply. They are therefore more susceptible to hypoxia. Additionally, they contain the greatest concentration of cytochrome p450 enzymes that metabolise substances into more reactive metabolites capable of killing the hepatocytes. Therefore toxic insults and conditions leasing to hypoxia commonly produce this pattern of necrosis. Some viral conditions, however, also result in centrilobular necrosis, such as '''[[Infectious Canine Hepatitis]] (ICH)'''. This is a highly infectious disease of young dogs caused by canine adenovirus-1. It is now rare in the UK and US due to effective vaccination protocols.
 ===Midzonal===

@@ Line 1: / Line 1: @@
 == Introduction ==
-Hepatocytic necrosis can occur following severe metabolic disturbances, toxic substances, nutritional deficiencies and through the action of micro-organisms.
+Hepatocytes are the epithelial cells of the liver, and these are the main targets of most liver diseases. They can ultimately undergo necrosis, a form of cell death, after lethal injury. This can occur following severe metabolic disturbances, toxic insults, nutritional deficiencies and through the action of micro-organisms.
 <br>
-[[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion.
+Despite many types of injury that the liver is subjected to, the resultant necrosis occurs in one of three patterns:
-== Random Foci (Focal)==
+== Random Necrosis (Focal)==
-Microscopic foci of necrosis are not related to any particular part of the liver lobule and can be due to a variety of insults such as, systemic viral, bacterial and parasitic infections and as a result of bacteria being absorbed from the gut.
+In this form of necrosis, there is no distinct pattern of lesions - small foci of necrosis are randomly scattered throughout the liver, and may be either microscopic or just visible to the naked eye. They can result from a variety of insults such as - systemic viral, bacterial and parasitic infections, or as a result of bacteria being absorbed from the gut.
 <br>
-Examples include
+Examples of conditions that result in random focal hepatic necrosis include:
-*[[Equine Herpesvirus 1|Equine herpes virus]] infection; necrosis found in aborted foetuses.
+*[[Equine Herpesvirus 1|Equine herpes virus 1]] infection found in aborted foetuses
-*[[Salmonellosis]]; necrosis found in the liver of calves due to the ''S. dublin'' serotype.
+*Septicaemia in association with [[Salmonellosis|salmonellosis]], tularaemia and [[Listeriosis|listeriosis]]
-*[[Toxoplasmosis - Cat and Dog|Toxoplasmosis]] (miliary necrosis), which is found in affected dogs and cats.
+*[[Toxoplasmosis - Cat and Dog|Toxoplasmosis]] in dogs and cats

← Older revision		Revision as of 23:06, 25 July 2011
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−
−
−	~~{{review}}~~
	[[Category:Liver_-_General_Pathology]]		[[Category:Liver_-_General_Pathology]]
−	[[Category:~~Expert_Review - Pathology~~]]	+	[[Category:Nicola Parry reviewing]]

@@ Line 1: / Line 1: @@
-== Causes ==
+== Introduction ==
 Hepatocytic necrosis can occur following severe metabolic disturbances, toxic substances, nutritional deficiencies and through the action of micro-organisms.
 <br>
 [[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion.
-<br>
+== Random foci (focal)==
+Microscopic foci of necrosis are not related to any particular part of the liver lobule and can be due to a variety of insults such as, systemic viral, bacterial and parasitic infections and as a result of bacteria being absorbed from the gut.
 <br>
 Examples include
-*Equine herpes virus infection; necrosis found in aborted foetuses.
+*[[Equine Herpesvirus 1|Equine herpes virus]] infection; necrosis found in aborted foetuses.
-*Salmonellosis; necrosis found in the liver of calves due to the S. dublin serotype.
+*[[Salmonellosis]]; necrosis found in the liver of calves due to the ''S. dublin'' serotype.
-*Toxoplasmosis (miliary necrosis), which is found in affected dogs and cats.
+*[[Toxoplasmosis - Cat and Dog|Toxoplasmosis]] (miliary necrosis), which is found in affected dogs and cats.
-======Periacinar (centrilobular)======
+== Zonal necrosis ==
-This is the most common type of zonal necrosis and occurs mainly due to the fact that the hepatocytes in this zone are furthest away from the incoming blood supply and are therefore less oxygenated and relatively anoxic. They are reported to contain the greatest number of enzymes responsible for metabolising sunstances to more toxic metabolites capable of killing the hepatocytes. Therefore hypoxic states and toxic substances predominate in this type of necrosis, although some viral conditions also cause this nerosis, such as '''Infectious Canine Hepatitis'''. This is a highly infectious disease of young dogs which is pread by urine. It is now rare due to vaccination in the UK.
+Zonal necrosis is necrosis occurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule:
-<br>
+===Periacinar (centrilobular)===
-======Midzonal=======
+===Midzonal===
-Midzonal necrosis is rare and is mainly seen in pigs with alfatoxicosis. It is also seen in humans suffering from 'Yellow Fever'.
+Midzonal necrosis is rare and is mainly seen in pigs with aflatoxicosis. It is also seen in humans suffering from 'Yellow Fever'.
 ======Periportal (centroacinar)======
 Centroacinar necrosis is also rare. This has been seen in cases of phosphorous poisoning.
 === Massive necrosis ===
-This occurs when there is necrosis of a complete acinus or an even larger area of tissue. It encompasses large areas of [[Liver - Anatomy & Physiology|liver]] cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ.
+This occurs when there is necrosis of a complete acinus or an even larger area of tissue. It encompasses large areas of liver cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ.
 <br>
 It can occur is some cases of ICH infection or carbon tetrachloride poisoning, with the severity of the injury replacing the zonal pattern.
-<br>
+==Subacute cytolytic necrosis==
-======Subacute cytolytic necrosis======
+==''Hepatosis dietica''==
-This is a condition in the dog, of which the aetiology is entirely unknown. Clinical symptoms include acute abdominal pain, collapse and invariably jaundice. Pathology shows the [[Liver - Anatomy & Physiology|Liver]] is normal or reduced in size and that there is severe necrosis.
+This is a similar condition to subacute cytolytic necrosis, but it occurs in rapidly growing pigs. It is thought to be related to diet and occurs in pigs fed on large quantities of grain concentrates, poor quality or low quantity protein supplements. This results in nutritional deficiencies of selenium and Vitamin E, and probably amino acids. It is thought to be triggered by stress.
-======''Hepatosis dietica''======
+==Test yourself with the Liver Pathology Flashcards==
 == References ==
-Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition), Elsevier Science.
+Blood, D.C. and Studdert, V. P. (1999) '''Saunders Comprehensive Veterinary Dictionary '''(2nd Edition),'' Elsevier Science.''
 <br>
-Ettinger, S.J, Feldman, E.C. (2005) Textbook of Veterinary Internal Medicine (6th edition, volume 2), W.B. Saunders Company.
+Ettinger, S.J, Feldman, E.C. (2005) '''Textbook of Veterinary Internal Medicine '''(6th edition, volume 2),'' W.B. Saunders Company.''
 <br>
-Fossum, T. W. et. al. (2007) Small Animal Surgery (Third Edition), Mosby Elsevier.
+Fossum, T. W. et. al. (2007) '''Small Animal Surgery''' (Third Edition),'' Mosby Elsevier.''
 <br>
-Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition), Mosby Elsevier.
+Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine '''(Fourth Edition)'', Mosby Elsevier. ''
 [[Category:Liver_-_General_Pathology]]
-[[Category:To_Do_-_Review]]
+[[Category:Expert_Review - Pathology]]

@@ Line 1: / Line 1: @@
-====Causes====
+== Causes ==
-*severe metabolic disturbances [as seen in degenerative pathology link?]
+Hepatocytic necrosis can occur following severe metabolic disturbances, toxic substances, nutritional deficiencies and through the action of micro-organisms.
-*toxic substances [link?]
+<br>
-*nutritional deficiencies
+[[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion.
-====Histological patterns====
+<br>
-*[[Liver - Anatomy & Physiology|Liver]] cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion
-=====Random foci (focal)=====
+=== Random foci (focal)===
-*microscopic foci of necrosis not related to any particular part of the [[Liver - Anatomy & Physiology|liver]] lobule
+Microscopic foci of necrosis is not related to any particular part of the [[Liver - Anatomy & Physiology|liver]] lobule and can be due to a variety of insults such as, systemic viral, bacterial and parasitic infections and as a result of bacteria being absorbed from the gut.
-*can be due to a variety of insults
+<br>
-**systemic viral, bacterial,and parasitic infections
+Examples include
-**result of bacteria being absorbed from the gut
+**Equine herpes virus infection; necrosis found in aborted foetuses.
-*examples
+**Salmonellosis; necrosis found in the liver of calves due to the S. dublin serotype.
-**Equine herpes virus infection
+**Toxoplasmosis (miliary necrosis), which is found in affected dogs and cats.
-***in aborted foetuses
-**Salmonellosis
+<br>
-***in calves
-**Toxoplasmosis (miliary)
+=== Zonal necrosis ===
-***in dogs and cats
+Zonal necrosis is necrosis ocurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule:
 ======Periacinar (centrilobular)======
-*most common
+======Midzonal=======
-*main reason is because the hepatocytes in this zone are furthest away from the incoming blood supply
+Midzonal necrosis is rare and is mainly seen in pigs with alfatoxicosis. It is also seen in humans suffering from 'Yellow Fever'.
-======Midzonal======
+<br>
 ======Periportal (centroacinar)======
-*rare
+Centroacinar necrosis is also rare. This has been seen in cases of phosphorous poisoning.
 ======Subacute cytolytic necrosis======
-*a condition in the dog
+This is a condition in the dog, of which the aetiology is entirely unknown. Clinical symptoms include acute abdominal pain, collapse and invariably jaundice. Pathology shows the [[Liver - Anatomy & Physiology|Liver]] is normal or reduced in size and that there is severe necrosis.
-*aetiology is entirely unknown
-*Clinical
+<br>
 ======''Hepatosis dietica''======
-*similar condition to subacute cytolytic necrosis
+This is a similar condition to subacute cytolytic necrosis, but it occurs in rapidly growing pigs. It is thought to be related to diet and occurs in pigs fed on large quantities of grain concentrates, poor quality or low quantity protein supplements. This results in nutritional deficiencies of selenium and Vitamin E, and probably amino acids. It is thought to be triggered by stress.
-*occurs in rapidly growing pigs
-*related to diet
-**fed on large quantities of grain concentrates
+<br>
-**poor quality or low quantity protein supplements
-*Cause
+== References ==
-**nutritional deficiencies of selenium and Vitamin E, and probably amino acids
+Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition), Elsevier Science.
-**triggering mechanism is environmental stress
+<br>
 ==Test yourself with the Liver Pathology Flashcards==
@@ Line 76: / Line 70: @@
 [[Category:Liver_-_General_Pathology]]
-[[Category:To_Do_-_Clinical]]
+[[Category:To_Do_-_Review]]