LP-9 Phillodes Tumor of the Breast: Histological Classification,

Phyllodes tumors (PTs) are rare biphasic neoplasms composed of benign epithelial elements and a cellular spindle cell stroma. They account for less than 1 % of all breast neoplasms and approximately 2.5 % of all fibroepithelial tumors [1]. Although they show many features of much commoner fibroadenomas, PTs are likely to recur and can be locally aggressive. In addition, a small percent of PTs show sarcomatoid features and have a potential to metastasize [2]. Phyllodes tumors usually occur as solitary unilateral tumors in middle aged women. On gross examination they are well circumscribed, vaguely lobulated, sometimes with leaf like fronds projecting into cystic spaces. One of the most characteristic histological features of PT is formation of variable sized cystic spaces lined with double layer of benign-looking epithelium into which projects hypercellular stroma. A cellular zonation may be noted with hypercellular areas in close vicinity to the epithelial surface, sclerotic changes at the periphery, and an admixture of fat/spindle cells in between