Stromal sarcoma of breast: a light and electron microscopic study.
A case of stromal sarcoma of the breast was studied by light and electron microscopy. The tumor comprised of uniform, plump spindle cells with neither epithelial nor "metaplastic" mesenchymal elements. Ultrastructurally most of the tumor cells appeared immature containing abundant free ribosomes, variable amounts of microfilaments and profiles of rough endoplasmic reticulum, with scant intercellular collagen and elastic fibers. The cells often showed prominent nesting as well as a variety of cell junctions, including desmosomes. We believe this tumor is a poorly differentiated, precursor mesenchymal sarcoma which belongs in the category of "stromal sarcoma of breast," a term coined by Berg et al. in 1962. To our knowledge, this represents the first published electron microscopic study on this tumor. Despite a high mitotic figure count in the tumor, the patient has survived a simple mastectomy with no evidence of metastasis 30 months later.