Sarcomas and related mesenchymal tumors of the breast

Abstract

The clinical and pathologic findings in 32 patients with mesenchymal neoplasms of the breast were analyzed to determine which pathologic features were related to clinical behavior. The neoplasms were similar to mesenchymal tumors elsewhere in the body except that heterologous differentiation to form bone, cartilage, muscle and fat was surprisingly frequent. Recurrent lesions occurred in 12 patients, all within 14 months of initial therapy, and eight patients died of tumor, all within 5 years. Pathologic features associated with a low risk of recurrence or of death were a pushing margin (one recurrence, no deaths) and minimal atypism of the tumor cells. The degree of mitotic activity correlated less clearly with behavior but it was apparent that any tumor with five or more mitotic figures per 10 high-power fields was capable of metastasis. Such features of the tumor as its size, its contour and the degree of its cellular atypism and mitotic activity should be given in future reports so that the reader can evaluate the potential of the neoplasm for himself.