Breast - nonmalignant
Inflammatory / infectious
Acute mastitis / breast abscess

Author: Nat Pernick, M.D. (see Authors page)

Revised: 25 July 2017, last major update March 2010

Copyright: (c) 2002-2017,, Inc.

PubMed Search: Acute mastitis breast abscess

Cite this page: Acute mastitis / breast abscess. website. Accessed October 22nd, 2018.
Definition / general
  • Mastitis occurs in 5 - 15% of postpartum primiparous women; 3% with mastitis have an abscess (BJOG 2004;111:1378)
  • Usually subareolar
  • Associated with lactation and cracks in nipple
  • Also associated with eczema, nipple dermatoses and postreduction mammoplasty
  • Bacteria often not isolated from culture
  • Pregnancy related infections are usually due to Staphylococcus; usually unilateral, often MRSA (Arch Surg 2007;142:881, Asian J Surg 2009;32:55), also Staphylococcus epidermidis (BMC Microbiol 2009;9:82)
  • Streptococcus usually causes diffuse infections leading to scarring but is uncommon today
  • Brucellosis is associated with ingestion of unpasteurized milk
  • Tuberculosis may occur in endemic areas (Med Princ Pract 2009;18:245)
  • Nonpregnancy related infections may be polymicrobial or associated with diabetes (Am J Med Sci 2009;338:123)
Clinical features
Case reports
Clinical images

Images hosted on other servers:

Abscess (Fusarium)

Microscopic (histologic) description
  • Central cavity with neutrophils and secretory material surrounded by inflammatory cells and eventually fibrosis
Microscopic (histologic) images

Images hosted on PathOut server:

AFIP fig 32: Staph abscesses are sharply
demarcated; bacteria are in central cavity

Squamous metaplasia of lactiferous ducts #1
plug of keratin debris fills lactiferous duct
which has metaplastic squamous epithelium

Squamous metaplasia of lactiferous ducts #2
squamocolumnar junction is displaced,
mild periductal lymphocytes are present

Images hosted on other servers:

Breast abscess

Cytology description
Differential diagnosis