Clinicopathological features of granulomatous lobular mastitis and mammary duct ectasia

Abstract

Granulomatous lobular mastitis (GLM) and mammary duct ectasia (MDE) are inflammatory diseases. However, only a limited number of studies have focused on characterizing their clinicopathological features. The aim of the present study was to investigate the etiology, clinicopathological characteristics and diagnosis of GLM and MDE. The clinical information and treatment of 118 female patients with pathologically-proven GLM or MDE were retrospectively analyzed in the present study. A total of 29 cases had GLM, 77 had MDE and 12 had GLM accompanied by MDE. GLM tends to occur in patients who have had their last birth within 5 years and are usually <40 years of age. GLM masses were usually larger than MDE masses and suppurated or ulcerated more easily. Histopathologically, GLM was characterized by a significant granulomatous inflammatory reaction centered on lobules. Compared with MDE, GLM had a higher incidence of granuloma and microabscess formation within the lobules and surrounding tissue. More multinucleated giant cells within granuloma were observed in patients with GLM than in those with MDE, while MDE was characterized by significant dilatation of the duct terminals and inflammatory changes in the duct wall and periductal tissues. When compared with patients with GLM, foam cells within the duct epithelium or surrounding stroma were more common in patients with MDE. The present study demonstrated that GLM and MDE had distinct clinicopathological characteristics. Further research is required in order to identify more appropriate treatment strategies for these specific types of breast inflammation.

Keywords: diagnosis; granulomatous lobular mastitis; mammary duct ectasia; pathology.

Figure 1.

(A) Granulomatous lobular mastitis manifested as a painful tender breast lump, accompanied by nipple retraction, redness of skin, abscess and ulcers on the surface of the skin. (B) A patient with MDE suffering from hypophysoma presenting with a painful, tender breast lump, accompanied by nipple retraction, abscess formation and redness of surface skin. (C) An overlapping case manifested as a widely distributed breast lump, with nipple retraction, abscess formation, and redness of the skin surface. MDE, mammary duct ectasia.

Figure 2.

(A and B) A patient with GLM exhibited irregular undefined hypoechogenicity and sonolucent fluid-filled area containing detailed spot-like echos, and a strong blood flow signal. (C and D) An MDE patient showed undefined inhomogeneous hypoechogenicity, with mammary duct dilation and a strong blood flow signal. GLM, granulomatous lobular mastitis; MDE, mammary duct ectasia.

Figure 3.

Mammographic appearance of mammary duct ectasia, showing asymmetric density accompanied by thickening and edema of the skin around the nipple. (A) Mediolateral oblique view. (B) Craniocaudal view.

Figure 4.

Typical histopathological features of (A-C) GLM and (D) MDE. (A) Intralobular granulomatous inflammation. (B) The normal structure of the lobule was damaged. (C) Centrilobular microabscess and lipid vacuoles. (D) Mammary duct dilation with concentrated intraductal secretions and chronic periductal inflammation. Lymphocyte and plasmocyte infiltration were observed with marked periductal fibrosis. GLM, granulomatous lobular mastitis; MDE, mammary duct ectasia. The magnification of hematoxylin and eosin staining was ×100.

Figure 5.

Characteristic appearance of GLM. (A) Intralobular granuloma formation. (B) A large number of inflammatory cells infiltrated the inflammatory focus, including neutrophil granulocytes, lymphocytes and a few plasmocytes. (C) Multinuclear giant cells surrounded by epithelioid macrophages, accompanied with inflammatory cell infiltration, were observed. (D) Several microabscesses formed inside the inflammatory focus. GLM, granulomatous lobular mastitis. The magnification of hematoxylin and eosin staining was ×100.