[Malignant cystosarcoma phylloides and squamous cell carcinoma of the breast. A rare tumor combination]

A case of squamous cell carcinoma infiltrating the stroma of cystosarcoma phylloides malignum is reported. A short review of prognosis and therapy is given on comparable cases. It is not uncommon to find squamous cell metaplasias in the dilated ducts of cystosarcoma phylloides. The combination of squamous cell carcinoma with this tumour, however, is a rarity.