Unilateral lupus mastitis.

Lupus mastitis is a rare clinical manifestation associated with systemic lupus erythematosus or discoid lupus erythematosus. It is necessary to make a correct diagnosis to differentiate it from inflammatory breast cancer. The histological study shows involvement of the adipose tissue of the breast with histopathological findings of cutaneous lupus erythematosus. Direct immunofluorescence detects the lupus band at the dermal-epidermal junction. The treatment of choice is hydroxychloroquine. We present a case of unilateral lupus mastitis in a patient with no previous diagnosis of lupus with complete remission after the use of hydroxychloroquine and topical corticosteroids.