BREAST - Fibrosarcoma

The lesion shown is circumscribed, by the skin on one surface and by fat and a little muscle on the undersurface. There is recognisable, apparently normal, breast tissue at one pole. The lesion is formed by an irregularly nodular mass in which there are large cystic spaces. There are also areas of haemorrhage apparent.
This lesion had been present for some years in a women who was 23 years old when the breast was removed. Histologically the solid areas are formed by spindle-shaped cells showing little variation in size and almost no mitotic activity. The lesion has been variously described as cystosarcoma phyllodes (foliage-like, branching protruberances of tumour tissue within cystic spaces) and as giant fibroadenoma. A small proportion of these tumours metastasize so that the name fibrosarcoma is probably appropriate. The patient is alive and well and free of metastatic disease 20 years after the breast was removed.