The treatment process of an extremely rare giant borderline phyllodes tumor of breast: case report and literature review.

Giant phyllodes tumors are rare fibroepithelial neoplasms, usually defined as >10 cm. It is often difficult for pathologists to distinguish fibroadenomas from phyllodes tumors and determine the malignant potential level. The current treatment principle is to ensure the extended resection of tumors with a margin of 1 cm or more. For patients with multiple local recurrences or large tumors after surgery, simple mastectomy is recommended. Axillary management should be considered when breast cancer is diagnosed at the same time. We now present a rare case: a female patient found a right breast mass in 2014, and the mass had continued to grow for more than 7 months, and she was ultimately diagnosed with a giant phyllodes tumor with a diameter of 30 cm. Extensive resection is a suitable method to treat smaller phyllodes tumors, but giant phyllodes tumors require mastectomy, so the patient in this case underwent a total mastectomy. We removed the mass completely without destroying the normal tissue and structure. The treatment effect was obvious, and no related adverse events occurred during or after the operation, the postoperative recovery was good, and the patient was discharged once she was verified to be in a stable condition. This case is the first reported case of a patient who had a giant borderline phyllodes tumor with a diameter of 30 cm, underwent total mastectomy, and was followed up for 6 months without recurrence. The long-term effect of the treatment will be further evaluated after 5 years.