Spontaneous regression of pulmonary metastases from a malignant phyllodes tumor.

We report a case of spontaneous regression of pulmonary metastases from a malignant phyllodes tumor. A 50-year-old woman was diagnosed with a breast phyllodes tumor. Computed tomography and positron emission tomography revealed multiple lung metastases. She underwent a mastectomy to control the pain of the enlarging breast mass. Histopathologic examination diagnosed a malignant phyllodes tumor. Without the administration of any adjuvant therapy, the follow-up chest computed tomography scan and positron emission tomography scan showed disappearance of the lung metastases 2 months after surgery.