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Surgical Pathology Criteria

Granulomatous Lobular Mastitis


  • Granulomatous lobulocentric inflammation nearly always associated with a prior pregnancy

Alternate/Historical Names

  • Granulomatous mastitis
  • Postlactational granulomatous mastitis

Diagnostic Criteria

  • Granulomatous inflammation
    • Multinucleated giant cells
    • Epithelioid histiocytes
    • Occasional features
      • Fat necrosis
      • Abscesses
      • Sinus tract
      • Eosinophils
    • Schaumann and asteroid bodies absent to rare
  • Centered on lobules
    • Extensive inflammation may obliterate lobulocentric character
    • Ductal and periductal inflammation usually minor
  • Nearly always follows pregnancy
    • Mean interval two years
    • Rarely remote
    • Has been associated with oral contraceptive use

Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting:: May 27, 2006

Supplemental studies

Infectious disease stains

  • Acid fast and fungal stains must be negative

Differential Diagnosis

  • Fungal and acid fast infections must be ruled out by stains and cultures


Granulomatous Lobular Mastitis Sarcoidosis
Centered on lobules Widespread distribution
Granulomas may not be well formed Well formed tight granulomas
Associated inflammtion may be extensive Frequently lacks extensive accompanying inflammation (naked granulomas)
May have associated fat necrosis and abscess Necrosis and abscess rare


Granulomatous Lobular Mastitis Mammary Duct Ectasia
Centered on lobules Centered on ducts
Granulomatous inflammation May have giant cells but usually lacks formed granulomas
Nearly all cases postpartum May occur without associated pregnancy


Granulomatous Lobular Mastitis Puerperal Mastitis
No infectious organisms Bacterial infection
Mean interval two years from delivery Recent delivery


  • Nearly always occurs after pregnancy
    • Mean interval 2 years
  • Rare associations reported
    • Oral contraceptive use
    • Systemic lupus erythematosus
    • Hyperprolactinemia
    • Erythema nodosum
  • Hard mass
    • Usually not subareolar
  • Treatment may be excision or steroids
    • May recur following excision


Inflammatory and Infectious Breast Lesions

  • Granulomatous lobular mastitis
  • Mammary duct ectasia
  • Puerperal mastitis
  • Specific infectious processes
    • Bacteria
      • Bartonella henselae (cat scratch disease)
      • Corynebacteria
    • Fungi
      • Actinomycosis
      • Blastomycosis
      • Cryptococcosis
      • Histoplasmosis
    • Mycobacterium tuberculosis
  • Vasculitis
    • Giant cell arteritis
    • Polyarteritis nodosum
    • Wegener granulomatosis


  • Rosen PP, Oberman HA. Tumors of the Mammary Gland, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 7, 1993
  • Going JJ, Anderson TJ, Wilkinson S, Chetty U. Granulomatous lobular mastitis. J Clin Pathol. 1987 May;40(5):535-40.
  • Yip CH, Jayaram G, Swain M. The value of cytology in granulomatous mastitis: a report of 16 cases from Malaysia. Aust N Z J Surg. 2000 Feb;70(2):103-5.
  • Donn W, Rebbeck P, Wilson C, Gilks CB. Idiopathic granulomatous mastitis. A report of three cases and review of the literature. Arch Pathol Lab Med. 1994 Aug;118(8):822-5.
  • Tse GM, Poon CS, Ramachandram K, Ma TK, Pang LM, Law BK, Chu WC, Tang AP, Cheung HS. Granulomatous mastitis: a clinicopathological review of 26 cases. Pathology. 2004 Jun;36(3):254-7.

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