Fat necrosis

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Fat necrosis
Other namesalso known as Balser's necrosis
Breast tissue showing fat necrosis 4X.jpg
Micrograph of breast tissue showing fat necrosis. H&E stain
Specialty Pathology

Fat necrosis is a form of necrosis that is caused by the action of lipases on adipocytes. [1] [2]

Contents

In fat necrosis, the enzyme lipase releases fatty acids from triglycerides. The fatty acids then complex with calcium to form soaps. These soaps appear as white chalky deposits. [3]

It is usually associated with trauma of the pancreas or acute pancreatitis. [3] [4] It can also occur in the breast, [5] the salivary glands [6] and neonates after a traumatic delivery. [7]

Signs and symptoms

Signs and symptoms of fat necrosis are presented below:

Causes

Fat necrosis occurs primarily in the breast and pancreas. Breast lesions are mostly caused by adipose tissue trauma or post-surgical complications (e.g. hypoxia). Pancreatic lesions arise as a result of the pathological release of pancreatic enzymes which digest surrounding adipose tissue. Fat necrosis is also a feature of some diseases that cause inflammation of subcutaneous fat (panniculitis). Examples of causes include but are not limited to:

Pathophysiology

Fat necrosis is the pattern of damage associated with the destruction of adipose tissue by trauma, hypoxia, or lipase digestion (e.g. pancreatitis). In the classic case of fat necrosis in severe acute pancreatitis, the necrosis arises because adipocytes in the peritoneum are broken and digested by inappropriately activated pancreatic enzymes. Stored triglycerides in the adipocytes are released and split by pancreatic lipases into fatty acids and glycerol molecules. The resultant fatty acids react with extracellular calcium to make calcium soaps (i.e. fatty acid salts) that give fat necrosis its characteristic chalky-white appearance. Fat necrosis is an example of dystrophic calcification because the calcification occurs at normal serum calcium levels. [11]

Besides pancreatitis, fat necrosis is also associated with conditions such as pancreatic carcinoma and pancreatic trauma. Although the peripancreatic region is the most commonly affected site in pancreatic disease (due to direct contact with enzymes), associated fat necrosis can occur around the body in subcutaneous tissue, hand and foot joints, and bone marrow. These extrapancreatic complications are known as pancreatic panniculitis. [12]

Beyond saponification and calcification, fat necrosis concludes with fibrosis and the formation of grey-yellow scar tissue. It is also possible for calcification to occur around the edges of a fatty necrotic lesion, enclosing the fat in a cyst. These "oil cysts" may persist for months to years without undergoing fibrosis. This is often the case in breast fat necrosis, where the underlying oil cysts can be visualised using sonography, X-Ray, CT, or MRI. [10]

Diagnosis

Although fat necrosis can be diagnosed through a routine checkup with a physician, called a physical, a patient can also perform a physical checkup on themselves. For additional diagnosis, a physician would request one or more of the following scans or tests.

Management

When fat necrosis is being felt by a physician or patient, it may feel larger, smaller, unchanged, or not felt at all (resolved). Fat necrosis usually does not require surgery, it usually requires a patient to meet with their physician and as long as the pain is not present there is nothing to be concerned about unless the patient is concerned about cosmetic abnormalities. However, if pain is present surgery is a form of treatment a patient can consider.

To keep track of benign fat necrosis a yearly mammogram is taken in order to observe it.

However, if fat necrosis consists of oily fluid a physician will go in with a needle to remove this liquid, which may be causing discomfort. Excision may be needed if the mass becomes solid or causes a cosmetic abnormality.

Prognosis

Getting diagnosed with fat necrosis of any kind can be a great cause for concern, as most individuals may mistake it for a malignant tumor. Fat necrosis of the breast is a prognosis that is benign and does not increase an individual's risk for various cancers. An individual's life expectancy does not decrease with this diagnosis.

Epidemiology

Fat necrosis in the breast occurs around 0.6%, this represents 2.75% of lesions that end up being benign. However, 0.8% of fat necrosis occurs from tumors of the breast, 1–9% occurs in breast reduction surgery. Individuals that are high risk include women around the age of 50yrs along with pendulous breasts. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Necrosis</span> Unprogrammed cell death caused by external cell injury

Necrosis is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal.

<span class="mw-page-title-main">Pancreatitis</span> Inflammation of the pancreas

Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancreatitis.

<span class="mw-page-title-main">Lipolysis</span> Metabolism involving breakdown of lipids

Lipolysis is the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and free fatty acids. It is used to mobilize stored energy during fasting or exercise, and usually occurs in fat adipocytes. The most important regulatory hormone in lipolysis is insulin; lipolysis can only occur when insulin action falls to low levels, as occurs during fasting. Other hormones that affect lipolysis include glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol.

<span class="mw-page-title-main">Adipose tissue</span> Loose connective tissue composed mostly by adipocytes

Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular endothelial cells and a variety of immune cells such as adipose tissue macrophages. Adipose tissue is derived from preadipocytes. Its main role is to store energy in the form of lipids, although it also cushions and insulates the body. Far from being hormonally inert, adipose tissue has, in recent years, been recognized as a major endocrine organ, as it produces hormones such as leptin, estrogen, resistin, and cytokines. In obesity, adipose tissue is also implicated in the chronic release of pro-inflammatory markers known as adipokines, which are responsible for the development of metabolic syndrome, a constellation of diseases, including type 2 diabetes, cardiovascular disease and atherosclerosis. The two types of adipose tissue are white adipose tissue (WAT), which stores energy, and brown adipose tissue (BAT), which generates body heat. The formation of adipose tissue appears to be controlled in part by the adipose gene. Adipose tissue – more specifically brown adipose tissue – was first identified by the Swiss naturalist Conrad Gessner in 1551.

<span class="mw-page-title-main">Breast augmentation</span> Surgical procedure

Breast augmentation and augmentation mammoplasty is a cosmetic surgery technique using breast-implants and fat-graft mammoplasty techniques to increase the size, change the shape, and alter the texture of the breasts. Augmentation mammoplasty is applied to correct congenital defects of the breasts and the chest wall. As an elective cosmetic surgery, primary augmentation changes the aesthetics – of size, shape, and texture – of healthy breasts.

<span class="mw-page-title-main">Panniculitis</span> Medical condition

Panniculitis is a group of diseases whose hallmark is inflammation of subcutaneous adipose tissue. Symptoms include tender skin nodules, and systemic signs such as weight loss and fatigue.

<span class="mw-page-title-main">Acute pancreatitis</span> Medical condition

Acute pancreatitis (AP) is a sudden inflammation of the pancreas. Causes, in order of frequency, include: a gallstone impacted in the common bile duct beyond the point where the pancreatic duct joins it; heavy alcohol use; systemic disease; trauma; and, in minors, mumps. Acute pancreatitis may be a single event; it may be recurrent; or it may progress to chronic pancreatitis.

<span class="mw-page-title-main">Chronic pancreatitis</span> Medical condition

Chronic pancreatitis is a long-standing inflammation of the pancreas that alters the organ's normal structure and functions. It can present as episodes of acute inflammation in a previously injured pancreas, or as chronic damage with persistent pain or malabsorption. It is a disease process characterized by irreversible damage to the pancreas as distinct from reversible changes in acute pancreatitis.

<span class="mw-page-title-main">Dystrophic calcification</span> Calcification occurring in degenerated or necrotic tissue

Dystrophic calcification (DC) is the calcification occurring in degenerated or necrotic tissue, as in hyalinized scars, degenerated foci in leiomyomas, and caseous nodules. This occurs as a reaction to tissue damage, including as a consequence of medical device implantation. Dystrophic calcification can occur even if the amount of calcium in the blood is not elevated and cause metastatic calcification. Basophilic calcium salt deposits aggregate, first in the mitochondria, then progressively throughout the cell. These calcifications are an indication of previous microscopic cell injury, occurring in areas of cell necrosis when activated phosphatases bind calcium ions to phospholipids in the membrane.

<span class="mw-page-title-main">Pancreatic enzymes (medication)</span> Amylase, lipase, and protease mixture.

Pancreatic enzymes, also known as pancreases or pancrelipase and pancreatin, are commercial mixtures of amylase, lipase, and protease. They are used to treat malabsorption syndrome due to certain pancreatic problems. These pancreatic problems may be due to cystic fibrosis, surgical removal of the pancreas, long term pancreatitis, pancreatic cancer, or MODY 5, among others. The preparation is taken by mouth.

Pancreatic diseases are diseases that affect the pancreas, an organ in most vertebrates and in humans and other mammals located in the abdomen. The pancreas plays a role in the digestive and endocrine system, producing enzymes which aid the digestion process and the hormone insulin, which regulates blood sugar levels. The most common pancreatic disease is pancreatitis, an inflammation of the pancreas which could come in acute or chronic form. Other pancreatic diseases include diabetes mellitus, exocrine pancreatic insufficiency, cystic fibrosis, pseudocysts, cysts, congenital malformations, tumors including pancreatic cancer, and hemosuccus pancreaticus.

<span class="mw-page-title-main">Calciphylaxis</span> Medical condition

Calciphylaxis, also known as calcific uremic arteriolopathy (CUA) or “Grey Scale”, is a rare syndrome characterized by painful skin lesions. The pathogenesis of calciphylaxis is unclear but believed to involve calcification of the small blood vessels located within the fatty tissue and deeper layers of the skin, blood clots, and eventual death of skin cells due to lack of blood flow. It is seen mostly in people with end-stage kidney disease but can occur in the earlier stages of chronic kidney disease and rarely in people with normally functioning kidneys. Calciphylaxis is a rare but serious disease, believed to affect 1-4% of all dialysis patients. It results in chronic non-healing wounds and indicates poor prognosis, with typical life expectancy of less than one year.

Lipid metabolism is the synthesis and degradation of lipids in cells, involving the breakdown and storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes. In animals, these fats are obtained from food and are synthesized by the liver. Lipogenesis is the process of synthesizing these fats. The majority of lipids found in the human body from ingesting food are triglycerides and cholesterol. Other types of lipids found in the body are fatty acids and membrane lipids. Lipid metabolism is often considered as the digestion and absorption process of dietary fat; however, there are two sources of fats that organisms can use to obtain energy: from consumed dietary fats and from stored fat. Vertebrates use both sources of fat to produce energy for organs such as the heart to function. Since lipids are hydrophobic molecules, they need to be solubilized before their metabolism can begin. Lipid metabolism often begins with hydrolysis, which occurs with the help of various enzymes in the digestive system. Lipid metabolism also occurs in plants, though the processes differ in some ways when compared to animals. The second step after the hydrolysis is the absorption of the fatty acids into the epithelial cells of the intestinal wall. In the epithelial cells, fatty acids are packaged and transported to the rest of the body.

<span class="mw-page-title-main">White adipose tissue</span> Fatty tissue composed of white adipocytes

White adipose tissue or white fat is one of the two types of adipose tissue found in mammals. The other kind is brown adipose tissue. White adipose tissue is composed of monolocular adipocytes.

Estrogenic fat is a form of adipose tissue which develops under the influence of estrogen, and particularly estradiol, in women.

Congenital generalized lipodystrophy is an extremely rare autosomal recessive condition, characterized by an extreme scarcity of fat in the subcutaneous tissues. It is a type of lipodystrophy disorder where the magnitude of fat loss determines the severity of metabolic complications. Only 250 cases of the condition have been reported, and it is estimated that it occurs in 1 in 10 million people worldwide.

Acquired generalized lipodystrophy is a rare skin condition that appears during childhood or adolescence, characterized by fat loss affecting large areas of the body, particularly the face, arms, and legs. There are 4 types of lipodystrophy based on its onset and areas affected: acquired or inherited, and generalized or partial. Both acquired or inherited lipodystrophy present as loss of adipose tissues, in the absence of nutritional deprivation. The near-total loss of subcutaneous adipose tissue is termed generalized lipodystrophy while the selective loss of adipose tissues is denoted as partial lipodystrophy. Thus, as the name suggests, AGL is a near-total deficiency of adipose tissues in the body that is developed later in life. It is an extremely rare disease that only about 100 cases are reported worldwide. There are three main etiologies of AGL suspected: autoimmune, panniculitis-associated, or idiopathic. After its onset, the disease progresses over a few days, weeks, months, or even in years. Clinical presentations of AGL are similar to other lipodystrophies, including metabolic complications and hypoleptinemia. Treatments are also similar and mainly supportive for symptomatic alleviation. Although HIV- or drug-induced lipodystrophy are a type of acquired lipodystrophy, its origin is very specific and distinct hence is usually not discussed with AGL.

<span class="mw-page-title-main">Breast mass</span> Localized swellings that feel different from the surrounding tissue

A breast mass, also known as a breast lump, is a localized swelling that feels different from the surrounding tissue. Breast pain, nipple discharge, or skin changes may be present. Concerning findings include masses that are hard, do not move easily, are of an irregular shape, or are firmly attached to surrounding tissue.

<span class="mw-page-title-main">Ductal cells</span>

Ductal cells refer to the epithelial cell lining of the pancreatic duct that deliver enzymes from the acinar cells to the duodenum. They have the essential function of producing bicarbonate-rich (HCO3-) secretion to neutralize stomach acidity. The hormone secretin stimulates ductal cells and is responsible for maintaining the duodenal pH and preventing duodenal injury from acidic chyme. Ductal cells mix their production with acinar cells to make up the pancreatic juice.

<span class="mw-page-title-main">Stem cell fat grafting</span>

Stem cellfat grafting is autotransplantation of adipose-derived stem cells (ADSCs) extracted from fat-abundant donor sites to other areas such as the face, breast, and hip to reconstruct the operative areas into desirable shapes. ADSCs are multipotent stem cells found in adipose tissues, displaying similar differentiation potentials to bone marrow-derived mesenchymal stem cells (BM-MSCs).

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