OVERVIEW

What is periductal mastitis?

Periductal mastitis is a common type of non-lactational mastitis in clinical practice. It is an inflammation of the subareolar ducts with an unclear etiology, primarily affecting young women but can also occur in men. Periductal mastitis differs from the traditional concept of "mammary duct ectasia."

What is non-lactational mastitis?

Non-lactational mastitis refers to a group of non-specific inflammatory diseases of unknown etiology that occur in women outside the lactation period, including periductal mastitis and idiopathic granulomatous mastitis (IGM).

SYMPTOMS

What are the manifestations of periductal mastitis?

Periductal mastitis is an inflammatory disease of the subareolar ducts, often manifested as periareolar inflammation.

• Inflamed ducts may develop secondary infections, leading to duct damage and subsequent duct rupture with abscess formation. Such abscesses often spontaneously rupture and drain at the areolar margin.

• Recurrent abscesses and draining fistulas (i.e., channels between the subareolar main duct and the skin) may also occur.

CAUSES

What are the causes of periductal mastitis?

The exact etiology remains unclear.

• Most patients with periductal mastitis are smokers, suggesting a link between smoking and subareolar duct damage, accompanied by tissue necrosis and subsequent infection.

• Periductal mastitis is also associated with squamous metaplasia, which may result from persistent inflammation.

DIAGNOSIS

What tests are needed for periductal mastitis?

Breast ultrasound is the preferred imaging method. Ductoscopy and ductography also have diagnostic value, allowing visualization of mammary duct obstruction, dilation, and cyst formation. However, these are invasive procedures with higher costs.

Additionally, CT, mammography, and MRI can aid in diagnosis, but these tests lack specificity and satisfactory resolution.

How is periductal mastitis diagnosed?

Diagnosis is difficult to confirm through imaging alone, often requiring needle biopsy.

What conditions should periductal mastitis be differentiated from?

Periductal mastitis must be distinguished from duct ectasia:

• Duct ectasia typically affects older women and is characterized by subareolar duct dilation with fibrosis. It presents with creamy or cheesy nipple discharge and nipple retraction. Dilated subareolar ducts may be clinically apparent and visible on imaging.

• Initially, duct ectasia and periductal mastitis were considered part of the same clinical syndrome, with the terms used interchangeably. However, duct ectasia is an age-related phenomenon without significant periductal inflammation or infection. Women with duct ectasia rarely have a history of periductal mastitis.

• Additionally, periductal mastitis must be differentiated from breast cancer.

TREATMENT

How to treat periductal mastitis?

• If there is significant breast pain, localized skin redness, elevated skin temperature, obvious tenderness, or even systemic infection symptoms such as fever and chills, the patient is considered to be in the acute inflammatory phase or may even have developed a breast abscess. In such cases, empirical antibiotic therapy, such as amoxicillin-clavulanate, should be administered.

• In cases of purulent nipple discharge, Gram staining and culture should be performed. Cultures are positive for pathogenic or potentially pathogenic microorganisms in 62%–85% of cases. The most common microorganisms include Staphylococcus, Enterococcus, anaerobic Streptococcus, Bacteroides, and Proteus.

• Additionally, smoking cessation helps reduce the risk of recurrent infections.

• For patients with confirmed subareolar abscesses, antibiotic therapy combined with abscess drainage is recommended, as subareolar abscesses treated solely by needle aspiration or incision and drainage often recur.

• If a periareolar fistula forms, the fistula should be opened or excised, with the excision of the fistula combined with complete duct removal.

• If periareolar infections recur frequently, duct excision is required for definitive treatment.

What are the surgical principles for periductal mastitis?

The surgical principle is to ensure complete and thorough removal of the lesion while preserving breast aesthetics.

Are antibiotics necessary during surgical treatment for periductal mastitis?

Antibiotic therapy for periductal mastitis should begin at the time of surgery and continue postoperatively until all signs of infection have resolved.

DIET & LIFESTYLE

Is periductal mastitis related to drinking soy milk?

Multiple domestic and international studies have shown that drinking soy milk is not associated with the occurrence of breast diseases. Moreover, soy milk provides rich protein, trace elements, and other nutrients, contributing to a balanced diet.

Do patients with periductal mastitis need to avoid certain foods?

Modern medicine does not recognize the concept of "food avoidance." As long as there is no allergy, as long as you want to eat, as long as you can tolerate it, and both your body and wallet can handle it, feel free to enjoy delicious food.

Is breast care or breast massage useful for periductal mastitis?

Medicine (whether traditional Chinese or Western) does not advocate for women to undergo so-called breast massage or breast care. Some patients, after discovering breast lumps or nodules, do not seek further diagnosis and treatment from formal medical institutions but instead receive "breast massage" from non-medical personnel, leading to rapid progression of early-stage breast cancer to advanced stages. Such tragic lessons have been repeatedly reported in the media.

PREVENTION

None.