ABSTRACT
Phyllode sarcoma is a rare lesion. Its epithelial component is usually benign and the mesenchymal component can differentiate into liposarcoma. These tumor has clinical and radiological characters of the benign lesions. But only the histological examination can diagnose and evaluate its prognosis. Carcinosarcoma of the breast results from a dedifferentiation of the invasive epithelial component found in the liposarcoma. The aim of our observation is to emphasize the clinical, radiological and the anatomo pathological discordances of these tumors and to underline the importance of the anatomopathological finding in its diagnosis and its impact on treatment. She is a 17-year-old girl, who has since one year a left breast lump and, after excision, a fast recurrence occurred. Echographic picture was in favour of a fibroadenoma. The tumour was diagnosed as a possible phyllode tumour. The histopathological and the immunochemistry findings proposed three diagnosis: a phyllod sarcoma with a heterogonous liposarcomatous stroma, a liposarcoma associated with an itracananicular carcinomas, carcinosarcoma with invasive differentiated carcinomatous components in a liposarcoma. Although physical and radiological examinations were in favour of a benign tumour, the anatomo pathological analysis proved the malignant nature of the tumour, and invited the surgeons to deal with the case as a carcinosarcoma due to its bad prognosis. Pathological analysis is therefore mandatory for diagnosis and the choice of treatment since, in our case, an aggressive treatment is necessary instead of a conservative one if the diagnosis of fibroadenoma was retained