Diagnosis and management of phyllodes tumors of the breast

Abstract

Phyllodes tumors are very uncommon and represent less than 1% of breast lesions. They may appear histologically and radiographically similar to fibroadenomas making definitive diagnosis challenging on core needle biopsy. Often the diagnosis of phyllodes may not be determined until surgical excision. Phyllodes tumors are characterized as benign, borderline, or malignant based on histologic criteria set forth by the World Health Organization. Surgical excision is the mainstay of treatment for all subtypes. When core needle biopsy is inconclusive, fibroepithelial lesions should be surgically excised though a wide margin is not necessary until a definitive diagnosis has been made. Wide local excision with 1cm margins has been advocated, though narrow margins with close observation may suffice for benign tumors. Positive margins are associated with greater recurrence risk and should be excised if feasible. Recurrence is common and may be treated with wide local excision. Radiation has been increasingly used for treatment in borderline and malignant phyllodes with improvement in local control though no improvement in overall survival. Malignant phyllodes tumors behave histologically similar to sarcomas with lung metastasis being most common. Nodal involvement is very uncommon given the propensity for hematogenous spread and routine nodal evaluation is not recommended. No trials have demonstrated a survival benefit to systemic therapy and most individuals presenting with metastatic disease have a poor prognosis.

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