[Postoperative pyoderma gangrenosum and cancer of the breast. Apropos of a case].

Pyoderma gangrenosum (PG) is a extending necrotic ulceration with bluish and purplish red margins. This disease is often associated with ulcerative colitis, systemic, hematologic or rheumatic affections. However post-surgical idiopathic PG can occur. One post-mammectomy case is reported. PG can first be suspected on clinical aspect, lack of a specific etiology. PG is a diagnosis of exclusion that is made only after others possibilities are ruled out. The treatment is surgical excision and general corticotherapy.