Phyllodes Tumors

Abstract

Phyllodes tumors are rare primary breast neoplasms graded as benign, borderline, or malignant based on pathology characterization of the stromal component. Core-needle biopsy is recommended as the first diagnostic step for breast lesions suspicious for phyllodes. Surgical excisional biopsy is recommended for a core-needle biopsy showing cellular fibroepithelial lesion or a mass suspicious for phyllodes tumor as pathology diagnosis is challenging, especially on limited tissue specimens. Surgical treatment parallels that for soft tissue sarcoma rather than breast adenocarcinoma. Wide local excision and mastectomy, with 1 cm tumor-free margins, provide equivalent oncologic outcomes. Tumor enucleation, subtotal resection, and positive final margins should be avoided. Axillary surgery is not recommended as lymph node metastases are rare. Adjuvant radiation is not recommended as routine, nor is adjuvant chemotherapy, although either or both may be considered for primary or recurrent high-risk malignant phyllodes tumors on a case-by-case basis. Local recurrence rates are influenced by margin status and tumor grade. Distant metastases occur in up to 25% of patients with borderline/malignant tumors and bestow a poor prognosis. Recent molecular genetic analyses of phyllodes tumors have identified potentially targetable mutations that may guide future therapy for high-risk, recurrent, or metastatic phyllodes tumors. This review contains 5 figures, 5 tables, and 53 references. Key words: biomarkers, breast sarcoma, diagnosis, outcomes, pathology, phyllodes tumor, surgery, treatment