CASE 14144 Published on 18.02.2017

Idiopathic granulomatous mastitis

Section

Breast imaging

Case Type

Clinical Cases

Authors

Funda Dinç Elibol¹, Cenk Elibol¹, Ahmet Korkut Belli², Okay Nazlı²

Department of Radiology¹, Mugla Sitki Kocman University Education and Research Hospital, Mugla/Turkey
Department of General Surgery², Mugla Sitki Kocman University Education and Research Hospital, Mugla/Turkey
Email:fundadi@yahoo.com

Patient

27 years, female

Categories

Area of Interest Breast ; Imaging Technique Ultrasound-Power Doppler, Ultrasound, MR

Procedure Contrast agent-intravenous ; Special Focus Inflammation ;

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Clinical History

A 27-year-old woman was presented with a progressively increasing tender lump, continuing swelling and mastalgia within the subareolar region of her left breast, lasting for 1 week. Her breastfeeding period lasted for 2 years and she had not breastfed for 1 year.

Imaging Findings

The initial sonogram revealed periareolar focal hypoechogenicity with minimal acoustic shadowing. Empirical antibiotherapy was initiated due to the diagnosis of non-lactating mastitis. Lumpiness and mastalgia persisted after antibiotheraphy. 2 weeks later, US showed a few masses containing internal echoes with smooth and indistinct margins connected to each other via tubular structures in the periareolar region of the left breast, in addition to previous US. Doppler US showed vascularity around hypoechoic lesions. During the first month, erythema nodosum was noted on the left leg and the sonogram showed progression. MRI revealed intensely and progressively enhancing regional non-mass enhancement. A percutaneous biopsy was recommended to BI-RADS 4 lesions to rule out malignancy, however, the patient and her physician preferred an excisional biopsy. Histopathology revealed features of idiopathic granulomatous mastitis. Microbiological studies ruled out tuberculosis. A corticosteroid therapy was initiated. The 2-month follow-up US showed a decrease in both size and number of lesions.

Discussion

Idiopathic granulomatous mastitis (IGM) is a rare benign, recurring inflammatory condition which clinically mimics carcinoma, first described in 1972 [1]. The aetiology of IGM is still unclear and controversial. The association with the autoimmune process, oral contraceptive pills, lactation, smoking, hyperprolactinemia, trauma have been suggested in the disease aetiology. Ethnicity may play a role in the disease [2]. The histopathological feature of IGM is non-necrotizing granuloma formation of lobules [3].
Breast lumps predominantly in the subareolar region and mastalgia are the most common clinical presentation [4, 5]. Extra-mammary signs are erythema nodosum, arthralgia, and episcleritis [6]. Because IGM clinically mimics other pathologies especially breast carcinoma, imaging is essential to rule out other pathologies [7]. Also, imaging features may mimic carcinoma and biopsy may be mandatory for diagnosis [5, 8].
The most common mammographic finding is focal asymmetric density in IGM [5, 8, 9]. Hypoechoic heterogeneous masses with characteristic tubular hypoechoic sinus tracts are the most frequent sonographic finding. Sonographic findings are variable and parenchymal heterogeneity with or without acoustic shadowing, architectural distortion, parenchymal oedema, isolated ill-defined hypoechoic heterogeneous lesions, fluid collections with mobile internal echoes are the other sonographic findings of IGM [5, 8, 10]. On Doppler ultrasound, increased vascularity of lesion and surrounding breast parenchyma is demonstrated [5, 10]. MRI findings are nonspecific and depend on the severity of the disease. MRI may be used to assess breast involvement and response to treatment [5].
The optimal treatment approach for IGM is controversial. It ranges from the conservative antibiotic, corticosteroid, methotrexate therapy to drainage of the wound and wide local excision [8-11]. Despite the treatment, IGM is frequently recurrent and in some cases refractory to treatment [11].
In conclusion, IGM may mimic malignant lesions both clinically and radiologically, so a histopathological diagnosis is essential before treatment.

Differential Diagnosis List

Idiopathic granulomatous mastitis

Tuberculosis

Wegener's granulomatosis

Carcinoma

Final Diagnosis

Idiopathic granulomatous mastitis

References

[1] Kessler E, Wolloch Y. (1972) Granulomatous mastitis: a lesion clinically simulating carcinoma. Am J Clin Pathol 58:642-6. (PMID: 4674439)

[2] Altintoprak F, Kivilcim T, Ozkan OV. (2014) Aetiology of idiopathic granulomatous mastitis. World J Clin Cases 16;2(12):852-8. (PMID: 25516860)

[3] Lacambra M1, Thai TA, Lam CC, et al. (2011) Granulomatous mastitis: the histological differentials. J Clin Pathol 64(5):405-11. (PMID: 21385894)

[4] Akcan A, Akyildiz H, Deneme MA, Akgun H, Aritas Y. (2006) Granulomatous lobular mastitis: a complex diagnostic and therapeutic problem. World J Surg 30(8):1403-9. (PMID: 16847715)

[5] Fazzio RT, Shah SS, Sandhu NP, Glazebrook KN. (2016) Idiopathic granulomatous mastitis: imaging update and review. Insights Imaging 7(4):531-9. (PMID: 27221974)

[6] Fahmy J, Halabi-Tawil M, Bagot M, Tournant B, Petit A. (2015) Erythema nodosum during the course of idiopathic granulomatous mastitis. Ann Dermatol Venereol 142(1):46-9. (PMID: 25600795)

[7] Bani-Hani KE, Yaghan RJ, Matalka II, Shatnawi NJ. (2004) Idiopathic granulomatous mastitis: time to avoid unnecessary mastectomies. Breast J 10(4):318-22. (PMID: 15239790)

[8] Sripathi S, Ayachit A, Bala A, Kadavigere R, Kumar S. (2016) Idiopathic granulomatous mastitis: a diagnostic dilemma for the breast radiologist. Insights Imaging 7(4):523-9. (PMID: 27164916)

[9] Seo HR, Na KY, Yim HE, et al. (2012) Differential diagnosis in idiopathic granulomatous mastitis and tuberculous mastitis. J Breast Cancer 15(1):111-8. (PMID: 22493637)

[10] Boufettal H, Essodegui F, Noun M, Hermas S, Samouh N. (2012) Idiopathic granulomatous mastitis: a report of twenty cases. Diagn Interv Imaging 93(7-8):586-96. (PMID: 22677299)

[11] Akbulut S, Yilmaz D, Bakir S. (2011) Methotrexate in the management of idiopathic granulomatous mastitis: review of 108 published cases and report of four cases. Breast J 17(6):661-8. (PMID: 21951547)

Case information

URL:	https://www.eurorad.org/case/14144
DOI:	10.1594/EURORAD/CASE.14144
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

1 month follow-up US

The first month control US showed hypoechoic lesions containing internal echoes with tubular hypoechoic extension. The initial sonogram showed just periareolar focal hypoechogenicity with minimal acoustic shadowing.

The other sonographic findings were tubular hypoechoic lesions containing internal echoes which were communicating with each other via thinner tubular extensions.

US revealed heterogenicity containing hypoechoic tubuler and spheric lesions with irreguler margins in periareolar region of left breast.

US revealed hypoechoic heterogeneous mass with tubular extensions, lobulated and irregular margins in the periareolar region of the left breast (BI-RADS 4).

US also revealed heterogeneity on fibroglandular tissue and well-defined hypoechoic spheric and tubular masses containing internal echoes.

Figure 2

Doppler US

Doppler US showed peripheral vascularity of hypoechoic lesions.

Figure 3

Movie of real-time ultrasound (the first month)

Play Video

Movie of real-time US showed BI-RADS 4 lesions which were masses containing internal echoes with smooth and indistinct margins connected to each other via tubular structures and heterogenicity in the periareolar region of the left breast.