benign breast phyllodes tumor
A usually unilateral, benign and well circumscribed biphasic neoplasm that arises from the breast. It usually affects middle-aged women. It is characterized by the presence of a double layer of epithelial cells that are arranged in clefts, surrounded by a cellular, monomorphic spindle cell mesenchymal component. Mitoses are rare. Necrotic changes may be present in large tumors.