Rapid Malignant Transformation of a Benign BreastPhyllodes Tumor: The Critical Role of Surveillance

Abstract

Phyllodes tumors are uncommon fibroepithelial breast neoplasms with a wide spectrum of biological behavior. Although surgery remains the treatment of choice, both diagnosis and management can be challenging. We report the case of a 78-year-old woman who was initially diagnosed with a benign lesion that was later reclassified as a benign phyllodes tumor. Based on this finding, she underwent mastectomy with immediate reconstruction, followed by adjuvant radiotherapy. A few months later, however, she developed a sarcomatous transformation,
followed by a local recurrence, which required re-excision with wider margins and removal of the implant. This case illustrates the diagnostic complexity of phyllodes tumors and emphasizes not only the importance of appropriate surgical management but also the need for close follow-up to identify early signs of potential malignant transformation.