Abses Payudara

01Pathophysiology

A breast abscess represents a localized collection of pus within the breast parenchyma. The mechanism differs based on whether the patient is lactating or not.

In lactational (puerperal) abscess, the sequence begins with milk stasis. When milk is inadequately drained from the breast, it accumulates within the ducts and creates a favorable medium for bacterial growth. Bacteria, most commonly Staphylococcus aureus, enter through microscopic skin breaks or fissures on the nipple surface that occur during breastfeeding. The resulting infection first manifests as mastitis (diffuse cellulitis of the breast tissue). If mastitis is not treated promptly or does not respond to antibiotics, the infection becomes walled off by an inflammatory capsule, forming a true abscess. This encapsulation is the reason antibiotics alone cannot resolve an established abscess, as the drug cannot penetrate a mature abscess wall at therapeutic concentrations.

In non-lactational abscess, the pathogenesis is different. The most common subtype is periductal (periareolar) abscess, strongly associated with smoking. Smoking causes squamous metaplasia of the lactiferous duct epithelium, replacing the normal columnar lining. This metaplastic epithelium produces keratin plugs that obstruct the duct, leading to duct ectasia, secondary bacterial infection, and abscess formation. The microbiology in non-lactating patients tends to be polymicrobial, often involving anaerobes and mixed skin flora. This is why recurrence is common in smokers who continue the habit.

Understanding this distinction is important because the test frequently presents a non-lactating woman with a periareolar mass and asks you to identify the risk factor (smoking) or the underlying histologic change (squamous metaplasia).

02Classification and Clinical Manifestation

A key clinical pearl: when a non-lactating, non-smoking older woman presents with a breast abscess, especially one that is recurrent or does not heal after standard treatment, always consider inflammatory breast carcinoma as a potential underlying cause. The test uses this scenario to assess whether students reflexively treat the abscess without pursuing further workup.

03Diagnostic Workup

Breast ultrasound is the best initial test. It confirms the presence of a drainable fluid collection, distinguishes abscess from cellulitis without a drainable component (mastitis alone), and can guide percutaneous needle aspiration. On ultrasound, a mature abscess appears as a hypoechoic lesion with thick, irregular walls and internal debris. Color Doppler shows increased vascularity in the surrounding inflamed tissue.

The distinction between mastitis and abscess is tested frequently. Mastitis presents as diffuse breast erythema, pain, and fever without a discrete fluctuant mass, and it responds to antibiotics alone. An abscess has a palpable fluctuant collection that requires drainage. When the clinical exam is equivocal, ultrasound is the deciding study.

Aspirated material must always be sent for culture and sensitivity. This is not optional. The rising prevalence of community-acquired MRSA means empiric coverage must account for resistance, and culture results allow de-escalation or adjustment. Gram stain provides rapid preliminary information.

In patients over 40 or those with features raising concern for malignancy (skin dimpling, bloody discharge, non-resolving mass), mammography and/or core biopsy should be performed after the acute infection resolves. Performing mammography during active infection is unreliable and painful.

04Management and Treatment

Acute management centers on source control. An abscess is a surgical disease in the sense that antibiotics alone cannot cure an established collection. The principle is straightforward: if there is pus, it must be drained.

For abscesses smaller than 3 cm, ultrasound-guided needle aspiration is preferred as the initial approach. It is less invasive, avoids a scar on the breast, and has comparable success rates for smaller collections. The cavity is aspirated to dryness, and the procedure may need to be repeated once or twice if the fluid reaccumulates. If the abscess does not resolve after 2-3 aspirations, formal I&D is indicated.

For abscesses 3 cm or larger, or those with overlying skin necrosis, I&D is the standard approach. The wound is left open and packed loosely, healing by secondary intention. Premature closure risks reaccumulation.

Antibiotic selection depends on the clinical context. In lactational abscess, the dominant organism is S. aureus, so empiric therapy targets staphylococci. In communities with high MRSA prevalence (>10-15%), empiric MRSA coverage with TMP-SMX or clindamycin is appropriate. For non-lactational periductal abscess, anaerobic coverage must be added because the flora is polymicrobial.

A frequently tested point: breastfeeding should not be discontinued. Continued nursing or pumping from the affected breast promotes drainage, reduces stasis, and does not transmit infection to the infant. The only exception is if the incision or drain site is so close to the areola that the infant would directly contact the wound.

For recurrent periductal abscess, definitive treatment requires excision of the involved duct (central duct excision) once the acute infection resolves. Without this, the cycle of obstruction and infection will repeat. Smoking cessation is also an integral part of long-term management.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on breast abscess questions is by selecting antibiotics alone as the answer when a drainable collection is present. The moment the vignette describes a "fluctuant mass" or ultrasound shows a fluid collection with debris, the answer must include drainage (either aspiration or I&D). Antibiotics without source control will not resolve a walled-off abscess.

The second classic trap is the non-lactating woman whose abscess does not resolve. If the vignette describes a breast abscess in an older, non-breastfeeding woman that persists despite adequate drainage and antibiotics, the next best step is tissue biopsy to rule out inflammatory breast carcinoma. Students who anchor on the infectious diagnosis and simply repeat drainage will miss the underlying malignancy.

Another commonly tested concept is the instruction to continue breastfeeding. The vignette may frame this as a follow-up question: "What do you advise the patient regarding breastfeeding?" The correct answer is to continue, not to stop. Stopping breastfeeding worsens milk stasis and paradoxically promotes abscess progression.

Finally, remember the smoking-squamous metaplasia-periductal abscess triad for non-lactating patients. When the question stem mentions a young female smoker with a recurrent periareolar mass, the underlying mechanism being tested is squamous metaplasia of the lactiferous ducts, and definitive management includes duct excision and smoking cessation.