title: [Erythema nodosum during the course of idiopathic granulomatous mastitis].
abstract: BACKGROUND
  Idiopathic granulomatous mastitis (IGM) is a benign, aseptic inflammatory disease of unknown origin, which must be distinguished from tumoral and infectious processes that affect the breast, including tuberculosis. IGM is a rare cause of erythema nodosum, but it is useful for dermatologists to be aware of this association.
  
  
  METHODS
  A 32-year-old nulliparous woman presented with erythema nodosum, arthralgia and fever. On examination, she had a firm and painful mass of 5cm in the right breast with retraction and axillary adenopathy. The breast lump developed gradually over the preceding 4 months. Although two biopsies showed no evidence of atypical cells, inflammatory areas and a granulomatous process were seen. Culture of breast tissue for mycobacteria was negative. A diagnostic of idiopathic granulomatous mastitis was made. Systemic corticosteroids led to a reduction in size of the mass, but relapse occurred in the contralateral breast on dose-reduction of the corticosteroids.
  
  
  CONCLUSIONS
  IGM is a rare disease of unknown aetiology. Diagnosis is based on characteristic histological features and exclusion of other granulomatous diseases. Extra-mammary signs are rare and include erythema nodosum, arthralgia and episcleritis. Management is poorly codified.
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France. Electronic address: fahmy.jihan@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Fahmy
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Halabi-Tawil
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Bagot
authors.affiliation: Centre des maladies du sein, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: B
authors.initials: B
authors.lastname: Tournant
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Petit
mesh_terms: D000328:Adult; D018771:Arthralgia / Q000150:complications; D004893:Erythema Nodosum / Q000150:complications*; D005260:Female; D005334:Fever / Q000150:complications; D058890:Granulomatous Mastitis / Q000150:complications*; D006801:Humans
keywords: Breast; Breast tuberculosis; Erythema nodosum; Granulomatous mastitis; Hypodermite; Mastite granulomateuse; Panniculitis; Sein; Tuberculose mammaire; Érythème noueux