Digital Atlas of Breast Pathology by Meenakshi Singh, MD © - Department of Pathology, Stony Brook University Medical Center
Phyllodes tumors are characterized by expansion and increased cellularity of the stromal component resulting in a leaf-like pattern. Increased stromal cellularity and mild cellular atypia can be seen in a benign phyllodes tumor. The mitotic rate should not be greater than 5 mitotic figures per 10 high power fields. Phyllodes tumors are rare, accounting for approximately 1% of all breast tumors. The patient typically has a history of a rapidly growing palpable breast mass. Note the benign appearing epithelium (left side of photomicrograph) in this high power image.