Benign phyllodes tumour of breast

**Definition:** A usually unilateral, benign and well circumscribed biphasic neoplasm that arises from the breast. It usually affects middle-aged women. It is characterised 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 tumours.

**Long definition:** Phyllode tumor is a rare fibroepithelial neoplasm accounting for less than 1% of all mammary tumors, usually presenting in adult females (most frequently between the ages of 35-55 years), ranging from benign to malignant and often presenting with well circumscribed mobile masses that grow rapidly and sometimes with additional non-specific symptoms such as dilated skin veins, nipple retraction, skin ulcers, palpable axillary lymphadenopathy or blue discoloration of the skin.