2023 Volume 37 Issue 6 Pages 527-532
A 52-year-old woman aged 42 years had undergone breast-conserving surgery after preoperative drug therapy (Fluorouracil/Epirubicin/Cyclophosphamide followed by eight courses of Docetaxel) for luminal HER2-type cancer in the left breast, with the chemotherapeutic grade classified as ypT1aN0M0 (ypStageIA). She underwent postoperative adjuvant hormone therapy (tamoxifen for 5 years and a luteinizing hormone releasing hormone derivative for 2 years) and anti-HER2 therapy (trastuzumab for 1 year) and was being followed up. A 10-mm nodule appeared in the upper lobe of her right lung on computed tomography at her 10-year follow-up examination, which was considered to be breast cancer metastasis. Partial lung resection was performed using thoracoscopy to confirm the diagnosis. Positron emission tomography showed a mass lesion with a standardized uptake value of 4.6 in the right retroperitoneum and upper pelvis, and the urologist resected the right renal ureter on suspicion of retroperitoneal tumor invasion. A diagnosis of metastatic lung tumor of retroperitoneal origin was made. Based on this case, when we suspect a solitary metastatic pulmonary nodule, we should also keep in mind that the nodule may have metastasized from an unexpected tumor.
