Inflammatory lesions of the breast or mastitis are complex and have multiples causes particularly cancer in its inflammatory form. The diagnosis of these pathologies is very difficult to confirm; it is based on the threefold support of clinical radiological and cytological examination. This diagnosis consists of looking for two sorts of mastitis: acute mastitis and sub-acute or chronic mastitis. The differential diagnosis of the various kinds of acute mastitis targets inflammatory cancer of the breast bacterial mastitis ecstasiant galactophoritis and collected abscess. As to chronic mastitis it may have several origins. There are mastitis of traumatic or cytosteatonecrotic origin mastitis with exogenous chemical origin mastitis of infectious origin including mammary tuberculosis hydatic cyst mammary syphilis mammary actinomycosis granulomatous mastitis cyphocytous lobulitis inflammatory cysts and galactocele. A mammography complemented by ultrasound and histology for biopsy serves for the diagnosis of these types of mastitis. The treatment of the inflamed breast consists of chemotherapy radiation therapy or surgery for chronic lesions the antibiotics associated with anti-inflammatory agents and local dressing for cases of acute mastitis.