Idiopathic Granulomatous
Mastitis (IGM)
Marwa Abo Elmaaty Besar
Lecturer Of Internal Medicine
(Rheumatology Immunology Unit)
(Pediatric Rheumatology)

Idiopathic granulomatous mastitis
(IGM)
 IGM is a rare benign chronic inflammatory condition of the breast.
 It is a rare breast pseudotumor.
 IGM characterised by non-caseating granulomas in the breast, often
with abscess formation.
 First described by Kessler and Wolloch in 1972.
 GM is rare, and incidence and prevalence have been difficult to
estimate.
 Incidence:
 2.4 per 100,000 women
 0.37% in the US, Europe is less.

 High risk group:
 non-white women.
 women of childbearing age, median age 30 years.
 Pregnant, first five year of pregnancy.
 lactation or hyperprolactinemia previous 5-6 years.
 Female using oral contraceptive pill.

The aetiology:-
 The exact etiology of GM is still unknown,
 A possible reason for GM is an inflammatory autoimmune response to epithelial damage,
although the trigger for this damage is still unknown.
 Hormonal changes:
 A correlation with breastfeeding and childbirth
 Might occur in response to extravasated secretions from the lobules.
 Bacterial infection;
 Corynebacterium kroppenstedtii has often been cultivated and may therefore play
a fundamental role in inducing this disease.
 lipophilic gram-positive rod, named ‘cystic neutrophilic granulomatous mastitis’

The aetiology:-
 Medication;
 Hyperprolactinemia provoked by antipsychotic medication
 Promote ductal ectasias and milk stagnation lead to inflammation.
 Alpha-1 antitrypsin deficiency
 Evidence of it is a potential risk factor for inducing GM
 Is an autosomal codominant disorder
 Is most prevalent in Caucasians of European or North American
descent.

Presenting Symptoms:-
 A very obscure presentation.
 The leading symptom of GM is a painful mass or as a hard irregular mass,
 Up to 50% of patients, erythema and swelling (inflammation of the involved
breast).
 Other symptoms; hyperemia, areolar retraction, fistula, and ulceration.
 Around 37% patients signs of an abscess.
 Lymphadenopathy is present in up to 15% of patients.
 Most lesions occur unilaterally.
 The lesion may occur in any quadrant of the breast but is mostly in the retro
areolar region from where it extends radially.

Differential Diagnosis:
 The mass may clinically mimic a bacterial abscess and/or breast cancer by
inducing skin or nipple retraction.
1. Granulomatous conditions
o Tuberculosis,
o Sarcoidosis,
o Wegener’s granulomatosis.
2. Other infection commonly involve breast:-
o histoplasmosis,
o actinomycosis,
3. Foreign body reaction, fat necrosis.
4. IgG4-RD mastitis,
5. Inflammatory breast cancer

Diagnosis:
 The diagnosis and treatment of a patient with GM still remains a
challenge
 The unspecific symptoms are often misleading in the diagnostic process.
 The patient suffer a protracted disease course with a significant impact on
quality of life.
 Different causes of mastitis, and most importantly malignancy, have to be
excluded before the diagnosis of GM
 The time period from the onset of symptoms to the exact diagnosis can
therefore be several months up to years.
 Radiographic images (Ultrasound, mammography, and magnetic
resonance imaging (MRI)) are nonspecific

 Imaging:-
 Ultrasound;
o Multiple contiguous hypoechoic masses with posterior acoustic shadowing or posterior acoustic enhancement.
o Advanced cases present with fluid collections and cavities in association with skin fistulas.
o hypervascularity which can be detected by Doppler imaging
o 15–55% of all cases show ipsilaterally enlarged reactive axillary lymph nodes
 Mammography:
o Unilateral focal or regional asymmetry as the most frequent pattern,
o 24% normal finding.
o Lesions were mammographically occult in 15 out of 45 women, because of an overlying dense breast pattern seen in
most women.
 MRI findings are also variable
o Heterogeneous ill-defined masses
o Non-mass enhancement, abscess formation, depending on the severity of the inflammation.
Breast Care 2018;13:413–418

 Laboratory Findings:-
o No blood-related factors to reliably support IGM.
o RF, ANA, ANCA (C,P), anti-dsDNA antibodies, interleukin 2 receptor, or angiotensin-
converting enzyme; NORMAL.
o C-reactive protein levels; unspecific marker of infection.
o The levels of carcinoembryonic antigen and cancer antigen (CA) within normal limit.

Histopathological assessment:
 The gold standard for diagnosing GM is core needle biopsy of the
lesion with a sensitivity of 96%,
o A non-necrotizing granuloma in combination with a localized infiltrate of
multi-nucleated giant cells, epithelioid histiocytes, lymphocytes, and
plasma cells.
o Organized sterile micro-abscesses occur with neutrophilic infiltrates.
o Inflammation that extends into adjacent lobules can indicate a higher
severity.
o The involved parenchyma mostly shows loss of acinar structures and
damaged ducts

Management:
 No consensus on disease management exists.
 A blind antibiotic therapy;
o Mastitis,
o without any microbiological proof of a bacterial infection.
o Therapy usually fails.
o The lowest efficacy with improvement rates ranging from 6 to 21%
 Drainage and aspiration
o Abscess puncture, drainage, or incision depending on the size of the
lesion
o Aspiration can fail because the abscess-like mass often has necrotic
tissue in the center that makes the aspirate thick and hard to extract.
Breast Care 2018;13:413–418

 Conservative strategy involving medical therapy with corticosteroids versus a surgical
approach.???????
 Medical therapy:
1. Corticosteroid:
o A high-dose corticosteroid therapy with prednisolone 30 mg/day for at least 2
months
o leads to a decrease in the diameter of the lesion.
o The duration of steroid varied between 2 and 6 months.
o a success rate of between 66 und 72%.
o a recurrence rate of 15% was reported.
o Despite these side effects, this approach became standard of care.

1. Methotrexate
 Indication: mainly for patients
o who have failed corticosteroid therapy.
o who have relapsed or
o who do not tolerate high-dose corticosteroid therapy
 low-dose regimen, 7.5–25 mg a weekly dose combined with folic acid applied daily or once a
week
 S/E;
o Ulcerative stomatitis, leukopenia,
o Nausea, abdominal distress,
o Undue fatigue, chills and fever, dizziness,
o Decreased resistance to infection.
 The evidence for this approach is limited and based on only a few case reports,
 Other immunosuprresion; azathioprine

 Surgical treatment: wide excision of the lesion
 The decision at what stage of the disease surgery is performed depends on the
individual clinical appraisal of the patient.
 The choice of surgical technique which varies from wide excision to mastectomy.
 Problem;
o Scars, asymmetry,
o Unsatisfactory esthetic results,
o Problems with breastfeeding.

Which is good?
 The decision whether surgery or medical treatment is preferred depend on
o Divergent regional resources,
o The patient’s expectations,
o Surveillance opportunities.
 Some authors primarily perform surgery mostly as a wide excision, others
start with a conservative regimen and switch to surgery when the medical
treatment fails.
 Surgery alone or in combination with corticosteroids seems to have the
lowest recurrence rates of 6.8 and 4%, respectively.
 There is a great variety of findings related to the risk of recurrence for the
different therapeutic approaches.

The local standards of the breast unit of ‘kliniken essen-mitte

Home message
 Idiopathic granulomatous mastitis (IGM) is a rare benign chronic
inflammatory condition of the breast but occur.
 IGM has clinical and imaging features similar to inflammatory breast
carcinoma.
 A definite diagnosis of idiopathic granulomatous mastitis always
requires a histopathological analysis .
 The treatment of choice for IGM has not yet been established,
corticosteroid or surgical should be individualized, expert opinion.

Reference:-
 Hovanessian Larsen LJ, Peyvandi B, Klipfel N, et al: Granulomatous lobular mastitis: imaging,
diagnosis and treatment. AJR Am J Roentgenol 2009; 193: 574–581.
 Akbulut S, Arikanoglu Z, Senol A, et al: Is methotrexate an acceptable treatment in the
management of idiopathic granulomatous mastitis? Arch Gynecol Obstet 2011; 284: 1189–1195.
 Bashir MU, Ramcharan A, Alothman SB, et al: The enigma of granulomatous mastitis: a series.
Breast Dis 2017; 37: 17–20.
 Calis H, Karabeyoglu SM: Follow-up of granulomatous mastitis with monitoring versus surgery.
Breast Dis 2017; 37: 69–72.
 Emre A, Akbulut S, Sertkaya M, et al: Idiopathic granulomatous mastitis: overcoming this important
clinical challenge. Int Surg 2017;Epub ahead of print.
 Huyser M, Kieran J, Myers S, et al: Review of idiopathic granulomatous mastitis in the Southwest
Native American population. Presentation at The American Society of Breast Surgeons, 19th Annual
Meeting 2018, Orlando.
 Moris D, Damaskos C, Davakis S, et al: Is idiopathic granulomatous mastitis a surgical disease? The
jury is still out ATM. Ann Transl Med 2017; 5: 309.
 Wong SCY, Poon RWS, Chen JHK, et al: Corynebacterium kroppenstedtii is an emerging cause of
mastitis especially in patients with psychiatric illness on antipsychotic medication. Open Forum
Infect Dis 2017; 4:ofx096.