Recurrent ductal squamous metaplasia of the breast

Specialty: Gynecology and breast.

• Recurrent periductal mastitis
• recurrent subareolar abscess
• Zuska disease

Why it occurs

• Chronic obstruction of the main lactiferous ducts in the retroareolar region due to keratinization and squamous metaplasia of the ductal epithelium (strongly linked to active smoking that alters the cellular differentiation of the duct), which favors the accumulation of keratin debris, recurrent anaerobic bacterial disease and persistent fistulas

Initial workup

High-resolution retroareolar breast ultrasound (dilated ducts with dense echogenic content, subareolar septated liquid collections and active fistulous tracts towards the skin are observed). Culture of pus from the fistula or abscess (anaerobes such as Bacteroides, Peptostreptococcus or gram-negative bacteria are frequently isolated). Core needle biopsy (CNB) of the wall of the induration if it persists to definitively rule out breast carcinoma.

Standard management

• Clindamycin 300 mg orally every 8 hours associated with Amoxicillin/clavulanic acid 875/125 mg every 8 hours for 14 days during acute outbreaks of fistulized abscess
• Metronidazole 500 mg every 8 hours orally associated with Ciprofloxacin 500 mg every 12 hours. The treatment of fluctuating abscesses is simple surgical incision and drainage. The definitive treatment of recurrent Zuska disease requires complete surgical resection of the affected milk duct and the fistula tract (Hadfield operation or fistulectomy with resection of the terminal ducts) once the acute inflammatory phase has passed (note: absolute cessation of smoking is the most important preventive factor to avoid recurrences).