[Spindle cell carcinoma of the breast : diagnostic difficulties].

The metaplastic breast cancers are rare lesions, accounting for less than 1 % of all breast malignancies. According to the WHO classification (2012), the spindle cell carcinoma of the breast figures among variants of metaplastic carcinomas. The average age at diagnosis is 53 years, and the usual course is fast. Their prognosis is more pejorative than the classic invasive ductal carcinoma. The differential diagnosis arises with sarcomas, especially phyllodes sarcomas but also with other primary breast sarcomas which remain rare. The distinction of this entity is important for further management of patients which is similar to that of conventional infiltrating carcinoma.