Inflammatory Disorders of the Breast Flashcards
What causes inflammatory disorders of the breast?
- Infections
- Autoimmune disease
- Foreign body-type reactions to extravasated keratin or secretions
How can inflammatory breast cancer mimic inflammation?
- Obstructing dermal vasculature with tumor emboli
- Should always be considered in a women with an erythematous swollen breast
What are some inflammatory disorders of the breast?
- Acute mastitis
- Squamous metaplasia of lactiferous ducts
- Duct ectasia
- Fat necrosis
- Lymphocytic mastopathy
- Granulomatous mastitis
What can all inflammatory disorders of the breast be confused with?
- Cancer
How do you tell inflammatory disorders apart from cancer?
- Look into the clinical setting, associations, biopsy findings, and treatment
When does acute bacterial mastitis typically occur?
- During the first month of breastfeeding
What causes acute bacterial mastitis?
- Local infection when the breast is most vulnerable due to cracks and fissures in the nipples
- Staphylococci infection often leads to single or multiple abscesses, whereas streptococci cause spreading infection in the form of cellulitis
What is squamous metaplasia of lactiferous ducts (SMOLD) also known as?
- Recurrent subareolar abscess
- Periductal mastitis
- Zuska disease
What does SMOLD present with?
- Painful, erythematous subareolar mass that mimics a bacterial abscess
- A fistula tract often develops under the smooth muscle of the nipple and opens onto the skin at the edge of the areola (esp. in recurrent cases)
- In many women, nipple inverts due to traction produced by inflammation and scarring
What is a common association with SMOLD?
- 90% of women affected are smokers
- Also suggested that a relative deficiency of vitamin A associated with smoking or toxic substances in tobacco smoke alters the differentiation of the ductal epithelium
What is the key feature of SMOLD?
- Keratinizing squamous metaplasia, which extends into the nipple duct well past the usual point of transition from squamous to glandular epithelium
What happens as the keratin sheds from the cells in SMOLD?
- Keratin cells are trapped and plug the ductal system causing dilation and eventually rupture of the duct
- This causes an intense chronic granulomatous inflammatory response to develop once keratin spills into the surrounding periductal tissue
- With recurrences, a secondary anaerobic bacterial infection may supervene and cause acute inflammation/abscess
How does duct ectasia present?
- Palpable periareolar mass that is often associated with thick, white nipple secretion and occasionally with skin retraction
When does duct ectasia present?
- Fifth or sixth decade in usually multiparous women
How is duct ectasia diagnosed?
- Due to difficulties in distinguishing it on clinical and radiologic grounds from invasive carcinoma, a radiopaque material is injected into the nipple to view the ductal structure
What are the ectatic dilated ducts filled with?
- Inspissated secretions and numerous lipid-laden macrophages
What happens in duct ectasia when the duct ruptures?
- A marked periductal and interstitial chronic inflammatory reaction ensues, consisting of lymphocytes, macrophages, and variable number of plasma cells
What does subsequent fibrosis cause in duct ectasia?
- An irregular mass with skin and nipple retraction
How does fat necrosis present?
- Commonly seen in the setting of trauma or surgery
- Painless, palpable mass, skin thickening or retraction, or mammographic densities or calcifications
What kind of necrosis is seen in fat necrosis?
- Liquifactive
What is lymphocytic mastopathy also known as?
- Sclerosing lymphocytic lobulitis
How does lymphocytic mastopathy present?
- Uncommon fibroinflammatory lesion that courses with the presence of benign breast nodules, and may clinically and radiologically mimic a carcinoma
- May appear as a single or multiple, uni or bilateral, synchronous or asynchronous, ill-defined, hardened mass
Who is most likely to have lymphocytic mastopathy?
- Women with T1DM (insulin dependent)
- Autoimmune thyroid disease
- Hypothesized to have an autoimmune basis
What are the masses in lymphocytic mastopathy associated with?
- Areas of densely collagenized stroma, a feature that may make it difficult to obtain lesional tissue by needle biopsy
What is the cause of granulomatous inflammation of the breast?
- Could be a manifestation of systemic granulomatous diseases or of inflammatory or infection disorders (sarcoidosis, TB)
Who is affected with granulomatous inflammation?
- ONly in parous women
What are the granulomas associated with in granulomatous inflammation?
- Lobules and may contain lipid vacuoles surrounded by neurtophils
What is the histologic pattern of granulomatous inflammation also seen in?
- Cystic neutrophilic granulomatous mastitis (caused by lipophilic Corynebacterium)
Who is most likely to have a localized infection due to either myobacteria or fungi?
- Immunocompromised patients
- Individuals that have foreign objects like a nipple piercing or breast prostheses
