Pôster:

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory breast disease of unknown etiology. The etiopathogenesis is associated with young pregnant women and lactation. Usually, the pathology has no specific antigen identified and histochemical tests are negative. IGM often mimics breast cancer but ultrasonographic findings of hypoechogenic confluent tubules with peri-lobular distribution and granulomatous inflammatory features are suggestive of this disease. The treatment is based on excisional biopsy however surgical results are aesthetically unfavorable. Corticosteroid therapy is intended to prevent recurrence of the disease and is prescribed in case of extensive lesions.

Case report

A 44 year-old female teacher presented for gynecologic evaluation because of a painful lump in right breast. On physical examination, there was a lesion of firm consistency, thick skin in the right breast, associated with erythema and fistulas. There were no papillary discharge or palpable adenopathies. The treatment was started with prednisone and cephalexin, furthermore laboratory tests and a skin biopsy were performed. The patient returned to the clinic with partial improvement of the pain and weight gain, being proposed corticosteroid weaning and a referral to the infectologist who required antinuclear antibody (ANA). ANA revealed a 1:640 dilution in centromere pattern therefore was referred to the rheumatology department due to CREST syndrome suspicious. She reports suffering from arthralgia and was taking prednisone and citalopram. She had no drug allergy, neither previous hospitalizations or chronic pathologies, gestational history of G2P2A0. She reported that her husband had been treated for Hansen's disease. The doctor requested complete blood count, creatinine, urea, glycemia, electrolytes, HBsAg, anti-HBs, anti-HBc, anti-HCV, HIV antibodies, C3, C4, anti-centromere antibody, serum protein electrophoresis, erythrocyte sedimentation rate (ESR), anti-DNA, anti-RO, anti-LA, anti-SM and two breast biopsies. She returned to the rheumatologist clinic with laboratory exams: anti-SM, anti-RO, anti-LA, anti-DNA, anti-HCV, anti-HIV, anti-HBc, HBsAg, purified protein derivative skin test, serum protein electrophoresis negatives, anti-HBs 16, anti-centromere 1:320, C3 140, C4 50, ESR 9, BI-RADS category 3, glycemia 70, creatinine 0.5, urea 25, sodium 141, noncaseous granulomas and chronic inflammatory disease of unknown aetiology.

Conclusion

Despite the positive antibody, no criteria for inflammatory disease have been developed. Considering the patient’s clinical history and the laboratory and histopathology findings, the diagnosis was interpreted as IGM and the physician prescribed prednisone and methotrexate, with good clinical response.