Idiopathic granulomatous mastitis with erythema nodosum simulating breast abscess in pregnancy: A case report.

Granulomatous mastitis is a rare benign inflammatory condition of the breast and is known to be associated with pregnancy. A 25-year-old Hispanic G2P1 at 17 weeks gestation presented to the emergency department with findings consistent of a breast abscess. The abscess failed to resolve with incision and drainage followed by multiple courses of antibiotic therapy. A biopsy was then obtained and yielded a diagnosis of granulomatous lobulitis. The patient was treated with steroids and her symptoms resolved. Granulomatous lobulitis may present with characteristics of various clinical entities including neoplasm or, as in this case, abscess. Clinicians should consider a diagnosis of granulomatous mastitis in cases of recalcitrant breast abscess.