71514 - Phyllodes Tumours: Interdisciplinary Management Recommendations from the Stockholm Region

Introduction Phyllodes tumours (PT) are fibroepithelial breast tumours divided into benign, borderline, and malignant PT. Method We here present the first Swedish practice guidelines for the clinical management of PT, from an interdisciplinary working group in the Stockholm region. Result PT should be suspected in patients over ≥ 30 years of age presenting with a fast-growing lump and/or a lump of ≥ 5 cm size. There are diagnostic challenges specific to PT, which are difficult to separate from fibroadenoma and other lesions on radiology. The preoperative work-up of breast lumps of ≥ 2 cm should involve a core needle biopsy, however, the sensitivity for PT is low with core needle biopsy and fine needle aspiration alike. Suspected borderline and malignant PT should be managed at a sarcoma centre, in collaboration between sarcoma surgeons and breast surgeons. All suspected PT should be discussed preoperatively at a multidisciplinary team meeting. For recommended excisional margins, see Table 1. Positive margins can be accepted for benign PT, which have a low risk of recurrence and no metastatic potential. Sentinel node biopsy is not indicated in surgery for PT. Immediate breast reconstruction is not advisable in cases of malignant PT, but may otherwise be offered. Post-operative follow-up is tailored to the subtype of PT, and for borderline and malignant PT involves both clinical and radiological surveillance. For malignant PT, adjuvant radiotherapy can sometimes be indicated and may prevent recurrence. Discussion We believe that these guidelines will be of clinical use in the work-up, management and follow-up of PT.