PReS-FINAL-2286: Mastitis in an adolescent patient with juvenile systemic lupus erythematous

Methods: Case report A 16 year-old girl presented with a painful left breast mass associated with localized skin erythema. Her medical history was significant for diffuse proliferative lupus nephritis that was diagnosed in 2002. After 2 years of immunosuppression therapy, the patient had stable renal function for more than 8 years. In January 2013, she presented with a painful nodule in the left breast. At the time of presentation, she had no clinical complaints but the serology findings were positive. There was no history of trauma to the breast, oral contraceptive use and negative sexual history. She was being treated with low dose prednisolone and azathioprine. The mass was warm and tender and no lymphadenopathy was present. The contralateral breast was normal. The laboratory tests showed normal blood count and negative inflammatory tests, ANA: 1/640 homogeneous pattern, anti-DNA: 1/80. Breast ultrasound revealed multiple areas with thick liquid collections in the subareolar region of the left breast. MRI confirmed the multiple cystic areas with subcutaneous thickening. An incisional biopsy revealed chronic inflammation, compromising lobes and stromal, compatible with inflammatory mastitis. Cultures were negative. The patient was treated with surgical drainage of collections associated to pulse therapy with methylprednisolone and mycophenolate mofetil was introduced featuring full resolution of the inflammatory process.