Clinical features of lupus mastitis:
(1) usually (but not always) the patient has a history of systemic lupus erythematosus (SLE)
(2) development of a breast mass that may be painful and which may show erythema and/or ulceration of the overlying skin
Imaging studies show:
(1) increased breast density due to progressive fibrosis which eventually leads to a decrease in breast size
(2) dystrophic calcifications which can progress to large, confluent sheets of calcifications
Histologic features:
(1) chronic inflammation with multifocal fat necrosis
(2) lymphocytic perivasculitis or necrotizing vasculitis
(3) dystrophic calcifications in areas of fat necrosis
(4) dense fibrosis
Differential diagnosis:
(1) breast carcinoma, especially inflammatory carcinoma
(2) lymphoma
(3) blunt trauma
(4) idiopathic granulomatous mastitis
