Idiopathic Granulomatous Mastitis

Abstract

NTRODUCTION: Idiopathic granulomatous mastitis is defined as granulomatous mastits without any other attributable cause. The condition is diagnosed very rarely. As the diagnosis is a lengthy differential diagnosis of exclusion there is considerable uncertainty about incidence. CASE REPORT: We present a case of a 37-year-old woman with an abnormal mammography exam. She observed a lump in the right breast about a year and a half ago that grew a lot. Mammography showed a focal assimetric in the upper lateral region of the right breast. Ultrasonography revealed a very suspicious lump in the region of the palpable mass, measuring 3, 5 cm. magnetic resonance imaging (MRI) of the breast revealed dense breasts with marked enhancement. The T2-weighted images showed an area of decreased attenuation, 4, 2 cm in diameter with spiculated borders, in the upper outer quadrant of the right breast. Four days later, a core needle biopsy of the breast mass was performed. Pathological examination of the specimen revealed granulomatous mastitis plus usual ductal hyperplasia. One day before the surgical lumpectomy, she presented with multiple lumps (at least 3) palpable in the same breast. The pathological finding was the same of the core needle biopsy. The treatment with glucocorticoids was started and 2 months later she presented with severe breast pain, no other abnormalities. We introduced endoxifen gel at that time and reduced de corticosteroids dose. One year later, she came to us concerned about local recurrence of a small lump. Again, we introduced oral prednisone and keep a short follow up. DISCUSSION: Like the diagnosis of sarcoidosis, the diagnosis of granlomatous mastitis requires exclusion of other causes of granulomatous disorders. Granulomatous mastitis may represent a localized autoimmune or hypersensitive response, but no evidence of imunne dysfunction or vasculitis was found in our patient. The clinical response of our patient to a prolonged course of low-dose prednisone was reasonable. The recurrence after one year is of undetermined prognosis, and more studies evaluating the dose, duration, medication and recurrence should be done.