Fat necrosis

Traumatic injury of adipose tissue liberates stored fat as well as lipases from adipocytes. The extracellular fat then elicits a swift inflammatory response, attracting macrophages and polymorphonuclear leukocytes which proceed to phagocytose the freed fat. The process eventually leads to fibrosis. The necrotic tissue may eventually form a palpable mass (especially if situated at a superficial site like the breast).

Traumatic fat necrosis commonly affects the breast and may resemble a tumour (especially in case of calcification of the necrotic mass).

Pancreatic conditions like acute pancreatitis, pancreatic carcinoma, and pancreatic trauma{{Cite journal |last1=Lee |first1=P. C. |last2=Howard |first2=J. M. |date=May 1979 |title=Fat necrosis |url=https://pubmed.ncbi.nlm.nih.gov/432796/ |journal=Surgery, Gynecology & Obstetrics |volume=148 |issue=5 |pages=785–789 |issn=0039-6087 |pmid=432796}} result in liberation of pancreatic lipase which proceeds to digest fat to form free fatty acids which subsequently combine with calcium to form soapy precipitates.

Although the peripancreatic region is the most commonly affected (due to direct contact with enzymes), associated fat necrosis may occur throughout the body in subcutaneous tissue, hand and foot joints, and bone marrow. These extrapancreatic complications are known as pancreatic panniculitis.

Examples of causes include but are not limited to:{{Citation needed|date=June 2024}}

• Breast trauma (e.g. seat belt injury from a car accident)
• Breast surgery
• Fine needle aspiration biopsy and cytology (FNAB, FNAC)
• Radiotherapy
• Lumpectomy
• Reduction mammoplasty
• Breast reconstruction
• Pancreatic disease
• Acute pancreatitis
• Pancreatic cancer
• Pancreatic injury
• Some forms of panniculitis
• Subcutaneous fat necrosis of the newborn
• Weber–Christian disease
• Polyarteritis nodosa{{Cite journal|last1=Kerridge|first1=William D.|last2=Kryvenko|first2=Oleksandr N.|last3=Thompson|first3=Afua|last4=Shah|first4=Biren A.|date=2015-03-16|title=Fat Necrosis of the Breast: A Pictorial Review of the Mammographic, Ultrasound, CT, and MRI Findings with Histopathologic Correlation|journal=Radiology Research and Practice|language=en|volume=2015|page=613139|doi=10.1155/2015/613139|pmc=4378709|pmid=25861475|doi-access=free}}{{Citation |last1=Genova |first1=Rafaella |title=Breast Fat Necrosis |date=2020 |work=StatPearls |url=http://www.ncbi.nlm.nih.gov/books/NBK542191/ |access-date=2020-11-12 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=31194348 |last2=Garza |first2=Robert F.}}

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.{{Cite journal |last1=Rice |first1=Hannah |last2=Warland |first2=Jane |date=October 2013 |title=Bearing Witness: Midwives experiences of witnessing traumatic birth |url=http://dx.doi.org/10.1016/j.wombi.2013.08.215 |journal=Women and Birth |volume=26 |pages=S39 |doi=10.1016/j.wombi.2013.08.215 |issn=1871-5192|url-access=subscription }}

• Caseous necrosis
• Coagulative necrosis
• Liquefactive necrosis
• Myospherulosis
• Necrosis

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• [http://breast-cancer.ca/necrofat/ Fat Necrosis of the breast]

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Category:Pathology

Category:Necrosis

Category:Breast diseases

Category:Pancreas disorders