Breast abscess

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

Breast abscess is a very rare infectious disease which is defined as a local collection of pus beneath the skin of the breast. It is the common complicated form of the breast inflammation (mastitis).

In 1841, Dr. Jonathan Toogood reported a case of breast abscess.^[1]

Breast abscess is classified according to the anatomical location of the abscess into subcutaneous, subareolar, interlobular, central and retromammary and the lactation state of the patient either lactational or non-lactational.

Following untreated mastitis, breast abscess could occur. Breast abscess is usually caused by staphylococcus aureus bacterial infection to an injured breast skin. Staphylococcus aureus could form abscess by secretion of several killing agents like enzymes and toxins which causes breast tissue necrosis. In a reaction to these bacterial substances, assembled white blood cells in this tissue produces anti-bacterial anti-bodies that help in killing the bacteria. However, these cells cause damage to the soft tissue contributing in the abscess formation. As the breast abscess is the complicated form of mastitis, the pathophysiology is mostly like the mastitis pathophysiology.^[2]

Breast abscess is a bacterial infectious disease that is caused by many bacterial pathogens and it may also be caused by fungi mostly common candida through the infant mouth. The most common bacterial pathogen causing breast abscess is the staphylococcus aureus. It is almost caused by the same pathogens causing mastitis. To understand the common species causing breast abscess we can classify them into gram positive and gram negative bacteria. ^[3][4][5]

Breast abscess should be differentiated from other diseases that cause swelling in the breast skin. These diseases are like mastitis, inflammatory breast cancer, galactocele, plugged duct, Mondor’s syndrome and fibroadenoma.^[6]

A breast abscess is a rare disease with an incidence of 3,000-11,000 cases only per 100,000 mastitis patients. There is no significant prevalence concerning the abscess.

The most important risk factor that can participate in breast infection and abscess formation is the trauma. Other risk factors include duct ectasia, obesity, diabetes mellitus and insect bites.

The breast abscess will rupture around its location on the skin if kept untreated. Complications of breast abscess include milk fistula and antibioma. Breast abscess prognosis is usually good with appropriate treatment but recurrence may occur.

Breast abscess can be noticed first by the patient like a breast mass or lump. The patient usually has current breast infection(mastitis) or history of the infection. The symptoms include fever, fatigue, skin induration and nipple discharge.

Patients with breast abscess are remarkable for the breast tenderness, swelling, redness and warmth of the skin.^{[7] [8]}

Breast abscess diagnosis depends only on the clinical manifestations of the abscess not the laboratory findings. However, a culture could be taken from the milk and the pus just to decide the antibiotics needed for the treatment.^[9]

There is no significant changes in the EKG of breast abscess patients.

There is no x-ray changes in the chest of breast abscess patients.

CT scan is not used to diagnose the breast abscess. However, it can be performed to exclude other diseases like breast cancer.

Ultrasonography is an important imaging approach in diagnosing and surgical treatment of breast abscess.

Mammography can be used in breast abscess diagnosis besides the US as it helps in differentiating between the breast abscess and cancer.

Medical treatment is important alongside the surgical treatment.Breast abscess is treated with antibiotics like flucloxacillin, dicloxacillin or erythromycin as a supportive line to the surgical measures and to prevent the abscess recurrance. The choice of the antibiotic medications depends on the pathogen type however, the high possibility of the pathogen to be staphylococcus aureus leads to start the antibiotic medications before the result of the discharge culture.[1].

The first line of breast abscess treatment is US guided needle aspiration and surgical drainage of the abscess.^[10]

Primary prevention of breast abscess relies on mitigation of the risk factors and improving patient hygiene particularly in lactating patients. It relies especially on the mother and infant hygiene. Breastfeeding is advised to be continued after the abscess drainage to prevent recurrence.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

In 1841, Dr. Jonathan Toogood reported a case of breast abscess.

In 1841, Dr. Jonathan Toogood described encountering only 4 to 5 cases in his career.^[1]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

Breast abscess is classified according to the anatomical location of the abscess into subcutaneous, subareolar, interlobular, central and retromammary and the lactation state of the patient either lactational or non-lactational.

Breast Abscess may be classified according to anatomical location and lactation state of the patient into subtypes.^[1]

• Anatomical location:
  • Subcutaneous
  • subareolar
  • Interlobular
  • Central
  • Retromammary

• Lactation state:
  • Lactational
  • Non-Lactational.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

Following untreated mastitis, breast abscess could occur. Breast abscess is usually caused by staphylococcus aureus bacterial infection to an injured breast skin. Staphylococcus aureus could form abscess by secretion of several killing agents like enzymes and toxins which causes breast tissue necrosis. In a reaction to these bacterial substances, assembled white blood cells in this tissue produces anti-bacterial anti-bodies that help in killing the bacteria. However, these cells cause damage to the soft tissue contributing in the abscess formation. As the breast abscess is the complicated form of mastitis, the pathophysiology is mostly like the mastitis pathophysiology.^[1]

Breast abscess is the result of underlying inflammation (mastitis) in the breast skin. Injury may happen either during the lactation process from the infant or in the non-lactaion state of the patient as a cracking in the breast skin. This injury accelerates the entry of the causative bacteria which by its role form the abscess. ^[2]
In neglected cases, there may be necrosis in the abscess location leads to fibrosis, scarring and nipple retraction.

• Lactational:
  • Injured breast skin allows the entrance of the bacteria to the mammillary ducts. This bacteria can be from the infant or the mother herself. Overproduction of the breast milk with no flow to the infant forms an opportunistic field for the bacteria to cause infection.^[3]
  • Breast Duct Ectasia: Metaplastic change of the duct cells can cause duct ectasia. This change causes widening of the ducts lining which leads to thickening of the ducts and obstruction. The ducts become filled with fluid which leads to nipple discharge and infection by the entrance of the bacteria and can form pus and abscess as a final result. ^[4]

• Non-Lactional:
  • Non lactational breast abscess is less common than lactational form. It can be subgrouped into central, peripheral and skin associating.
  • Cracking in the skin will overtly help the bacteria to enter and form the abscess.

There is no associated diseases with breast abscess.

The gross findings can be confused with other malignant diseases.

• Ill-defined with overlying skin thickening
• Lymphadenopathy
• Nipple retraction

The following findings can be demonstrated on a pathology slide

• Lymphocytes along with neutrophils are gathered around the central abscess cavity filled with pus.
• Inflammatory infiltration involves gland buds and surrounding stroma along with lymphatic ducts.
• Foamy histiocytes are demonstrated in the dilated ducts.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

Breast abscess is a bacterial infectious disease that is caused by many bacterial pathogens and it may also be caused by fungi mostly common candida through the infant mouth. The most common bacterial pathogen causing breast abscess is the staphylococcus aureus. It is almost caused by the same pathogens causing mastitis. To understand the common species causing breast abscess we can classify them into gram positive and gram negative bacteria. ^[1][2][3]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2] Shadan Mehraban, M.D.[3]

Breast abscess should be differentiated from other diseases that cause swelling in the breast skin. These diseases are like mastitis, inflammatory breast cancer, galactocele, plugged duct, mondor’s syndrome and fibroadenoma.^{[1][2] [3][4][5][6][7][8][9][10][11]}

Breast abscess must also be differentiated from the following conditions:

• Cystosarcoma phyllodes
• Breast cyst
• Breast carcinoma
• Lymphangioma
• Hemangioma
• Lipoma

Differentiation of breast abscess from different types of breast lumps:

ABBREVIATIONS
LAP=Lymphadenopathy, HRT=Hormonal replacement therapy, FNA=Fine needle aspiration, DCIS=Ductal carcinoma in-situ

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

A breast abscess is a rare disease with an incidence of 3,000-11,000 cases only per 100,000 mastitis patients. There is no significant prevalence concerning the abscess.

• The incidence of breast abscess is 3,000-11,000 per 100,000 of patients with mastitis.
• The incidence of breast abscess is only 100-3,000 per 100,000 of the puerperal patients. ^[1][2]

• Patients of all age groups may develop breast abscess.
• Breast abscess is more common observed in the infants and the young more than the elder.
• It is common in neonates with mastitis as approximately 50 percent of the neonatal patients with mastitis can develop breast abscess.^[3]

Breast abscess occurs commonly in women. It is very rare in men.

Breast abscess is more prevalent in the african american race.^[4]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

The most important risk factor that can participate in breast infection and abscess formation is the trauma. Other risk factors include duct ectasia, obesity, diabetes mellitus and insect bites.

• The most important risk factor of breast abscess is trauma.Trauma increases the possibility of the abscess formation as it facilitates the entrance of the causative bacteria into the soft tissue. Trauma can take place by different ways like shaving subareolar hair, piercing of nipple, infant’s mouth during breastfeeding and picking acne lesions.
• Smoking: increases the chances of abscess recurrence^[1]
• Obesity
• Diabetes mellitus
• Duct ectasia of the breast
• Local skin infection

These risk factors are related more to the non-lactational breast abscess:^[2]

• Insect bites
• Increasing age
• Surgical treatment: increases recurrence rate of the abscess^[1]

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

There is insufficient evidence to recommend routine screening for breast abscess.

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

The breast abscess will rupture around its location on the skin if kept untreated. Complications of breast abscess include milk fistula and antibioma. Breast abscess prognosis is usually good with appropriate treatment but recurrence may occur.

There is no significant natural history regarding the breast abscess. However, the abscess generally if not treated it will rupture around its site or necrosis will take place.

Complications that can develop in cases of breast abscess are:

• Milk fistula: A very rare complication that may occur in the lactating patient. It is defined as an opening between the lactiferous duct to the skin causing leakage of the milk on the skin.
• Antibioma: Chronicity of the breast abscess, a condition that may take place in case of using antibiotics for a long time without surgical drainage of the abscess.

Breast abscess prognosis is good with treatment but it has a high recurrence rate. In non lactational abscess has a high chance of recurrence (more than 50% of the cases).^[1] In the lactational abscess the chance of recurrence is around 35-50% of the cases.^{[2] [3]}

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