Medical and surgical treatment of idiopathic granulomatous lobular mastitis: a benign inflammatory disease mimicking invasive carcinoma

Abstract

Purpose: Idiopathic granulomatous lobular mastitis (IGLM) is a rare chronic inflammatory disease of the breast with obscure etiology that mimics invasive carcinoma both clinically and radiologically. The treatment of IGLM remains controversial. The aim of proper management is to use a combination of medical and surgical treatment of this benign condition to achieve a good cosmetic result and low recurrence rate.

Methods: A retrospective analysis of 19 patients with IGLM is performed based on the findings of clinical, radiological, and pathological examinations. The results of two treatments are presented: medical treatment with oral corticosteroids, and consecutive surgical excision after a follow-up period of 20 months (range, 6-75 months).

Results: The majority of patients treated in this paper were young (mean, 34 years) parous women with a history of hormonal medication use. The main clinical finding is large, irregular, and painful mass. Hypoechoic lobulated, irregular tubular or oval shaped masses had been imaged by ultrasound. Mammographic findings were an ill-defined mass, enlarged axillary lymph nodes, asymmetric density, and architectural distortion. Diagnoses of IGLM had been established by cytological or histological examination. Symptoms subside and inflammatory changes regressed with medical treatment. The remaining lesions were excised by consecutive breast conserving surgery. The disease recurred in one patient during the follow-up period.

Conclusion: IGLM is an inflammatory breast disease found in young women who present with a large painful irregular mass, which mimics carcinoma, as a physical change. Breast imaging modalities are not helpful to differentiate IGLM from invasive cancer. The correct diagnosis is established by cytological or histological examination. Medical treatment with corticosteroids provides significant regression of the inflammatory disease, allowing more conservative surgery. Consecutive surgical excision of the remaining lesions with good cosmetic results provides definitive treatment and reduces the risk of recurrence.

Keywords: Breast; Carcinoma; Corticosteroid; Mastectomy; Mastitis.

Figure 1

Skin lesions of a patient with idiopathic granulomatous lobular mastitis. Clinical presentation may mimic locally advanced breast carcinoma.

Figure 2

Mammographic finding (craniocaudal view). It shows asymmetric density.

Figure 3

Magnetic resonance imaging. It shows a heterogeneous mass.

Figure 4

Fine needle aspiration cytology finding. It shows a huge granuloma formation, with chronic inflammatory cells in the background (PAP, ×100 [Inlet magnification is ×200]).

Figure 5

Microscopic finding of operative specimen. It shows dilated intermediary-sized ducts with a surrounding inflammatory infiltrate of lymphocytes, plasma cells, and granuloma formation (H&E stain, ×100 [Inlet magnification is ×200]).

Figure 6

Gross finding after medical treament. The skin lesions regressed markedly.

Figure 7

Operation wounds after excision of remaining lesions. It shows good cosmetic results.