Coexistence of benign phyllodes tumor and invasive ductal cancer in the ipsilateral breast: A case report

Introduction and importance: Phyllodes tumors (PTs) are rare breast neoplasms, with an incidence rate of <1 %. Further, the coexistence of PTs and carcinoma is also uncommon. In this report, we describe a rare case of the synchronous coexistence of a benign PT and invasive ductal carcinoma (IDC) of the ipsilateral breast. Case presentation: A 42-year-old woman presented with a 6-month history of a tumor in her right breast. Mammography and ultrasonography revealed a 9.0 cm breast lump, and core biopsy revealed a benign PT. A simple mastectomy of the right breast revealed IDC foci in the mammary area, close to the benign PT. Right axillary lymph node staging was performed by surgery. However, no lymph node metastasis was observed. Subsequently, appropriate adjuvant therapy was initiated. Currently, the patient is doing well. Clinical discussion: Breast cancer may be located close to the PT of the ipsilateral breast and is difficult to detect preoperatively, especially in cases of large PTs. Early detection of the presence of a coexisting carcinoma is clinically important because it can alter patient management. Conclusion: Careful assessment of the PT using additional breast imaging tools might help identify their coexistence with breast cancer in cases of difficult diagnosis of coexistent tumors using standard breast imaging tools such as mammography or ultrasound.